Question: What is the highest elevation in the country where the Yongle Emperor sent Yang Sanbao?

full_context: Document 1: Tibet: Tibet has some of the world's tallest mountains, with several of them making the top ten list. Mount Everest, located on the border with Nepal, is, at 8,848 metres (29,029 ft), the highest mountain on earth. Several major rivers have their source in the Tibetan Plateau (mostly in present-day Qinghai Province). These include the Yangtze, Yellow River, Indus River, Mekong, Ganges, Salween and the Yarlung Tsangpo River (Brahmaputra River). The Yarlung Tsangpo Grand Canyon, along the Yarlung Tsangpo River, is among the deepest and longest canyons in the world.
Document 2: Sino-Tibetan relations during the Ming dynasty: Patricia Ebrey writes that Tibet, like Joseon Korea and other neighboring states to the Ming, settled for its tributary status while there were no troops or governors of Ming China stationed in its territory. Laird writes that "after the Mongol troops left Tibet, no Ming troops replaced them." Wang and Nyima state that, despite the fact that the Ming refrained from sending troops to subdue Tibet and refrained from garrisoning Ming troops there, these measures were unnecessary so long as the Ming court upheld close ties with Tibetan vassals and their forces. However, there were instances in the 14th century when the Hongwu Emperor did use military force to quell unrest in Tibet. John D. Langlois writes that there was unrest in Tibet and western Sichuan, which the Marquis Mu Ying (沐英) was commissioned to quell in November 1378 after he established a Taozhou garrison in Gansu. Langlois notes that by October 1379, Mu Ying had allegedly captured 30,000 Tibetan prisoners and 200,000 domesticated animals. Yet invasion went both ways; the Ming general Qu Neng, under the command of Lan Yu, was ordered to repel a Tibetan assault into Sichuan in 1390.
Document 3: Sino-Tibetan relations during the Ming dynasty: Historians Luciano Petech and Sato Hisashi argue that the Ming upheld a "divide-and-rule" policy towards a weak and politically fragmented Tibet after the Sakya regime had fallen. Chan writes that this was perhaps the calculated strategy of the Yongle Emperor, as exclusive patronage to one Tibetan sect would have given it too much regional power. Sperling finds no textual evidence in either Chinese or Tibetan sources to support this thesis of Petech and Hisashi. Norbu asserts that their thesis is largely based on the list of Ming titles conferred on Tibetan lamas rather than "comparative analysis of developments in China and Tibet." Rossabi states that this theory "attributes too much influence to the Chinese," pointing out that Tibet was already politically divided when the Ming dynasty began. Rossabi also discounts the "divide-and-rule" theory on the grounds of the Yongle Emperor's failed attempt to build a strong relationship with the fifth Karmapa—one which he hoped would parallel Kublai Khan's earlier relationship with the Sakya Phagpa lama. Instead, the Yongle Emperor followed the Karmapa's advice of giving patronage to many different Tibetan lamas.
Document 4: Sino-Tibetan relations during the Ming dynasty: Shih-Shan Henry Tsai writes that the Yongle Emperor sent his eunuch Yang Sanbao into Tibet in 1413 to gain the allegiance of various Tibetan princes, while the Yongle Emperor paid a small fortune in return gifts for tributes in order to maintain the loyalty of neighboring vassal states such as Nepal and Tibet. However, Van Praag states that Tibetan rulers upheld their own separate relations with the kingdoms of Nepal and Kashmir, and at times "engaged in armed confrontation with them."
Document 5: Tibet: Tibet (i/tᵻˈbɛt/; Wylie: Bod, pronounced [pʰø̀ʔ]; Chinese: 西藏; pinyin: Xīzàng) is a region on the Tibetan Plateau in Asia. It is the traditional homeland of the Tibetan people as well as some other ethnic groups such as Monpa, Qiang and Lhoba peoples and is now also inhabited by considerable numbers of Han Chinese and Hui people. Tibet is the highest region on Earth, with an average elevation of 4,900 metres (16,000 ft). The highest elevation in Tibet is Mount Everest, earth's highest mountain rising 8,848 m (29,029 ft) above sea level.
Document 6: Tibet: The Tibetan name for their land, Bod བོད་, means "Tibet" or "Tibetan Plateau", although it originally meant the central region around Lhasa, now known in Tibetan as Ü. The Standard Tibetan pronunciation of Bod, [pʰøʔ˨˧˨], is transcribed Bhö in Tournadre Phonetic Transcription, Bö in the THL Simplified Phonetic Transcription and Poi in Tibetan pinyin. Some scholars believe the first written reference to Bod "Tibet" was the ancient Bautai people recorded in the Egyptian Greek works Periplus of the Erythraean Sea (1st century CE) and Geographia (Ptolemy, 2nd century CE), itself from the Sanskrit form Bhauṭṭa of the Indian geographical tradition.
Document 7: Tibet: The modern Standard Chinese exonym for the ethnic Tibetan region is Zangqu (Chinese: 藏区; pinyin: Zàngqū), which derives by metonymy from the Tsang region around Shigatse plus the addition of a Chinese suffix, 区 qū, which means "area, district, region, ward". Tibetan people, language, and culture, regardless of where they are from, are referred to as Zang (Chinese: 藏; pinyin: Zàng) although the geographical term Xīzàng is often limited to the Tibet Autonomous Region. The term Xīzàng was coined during the Qing dynasty in the reign of the Jiaqing Emperor (1796–1820) through the addition of a prefix meaning "west" (西 xī) to Zang.
Document 8: Tibet: The Indus and Brahmaputra rivers originate from a lake (Tib: Tso Mapham) in Western Tibet, near Mount Kailash. The mountain is a holy pilgrimage site for both Hindus and Tibetans. The Hindus consider the mountain to be the abode of Lord Shiva. The Tibetan name for Mt. Kailash is Khang Rinpoche. Tibet has numerous high-altitude lakes referred to in Tibetan as tso or co. These include Qinghai Lake, Lake Manasarovar, Namtso, Pangong Tso, Yamdrok Lake, Siling Co, Lhamo La-tso, Lumajangdong Co, Lake Puma Yumco, Lake Paiku, Lake Rakshastal, Dagze Co and Dong Co. The Qinghai Lake (Koko Nor) is the largest lake in the People's Republic of China.
Document 9: Sino-Tibetan relations during the Ming dynasty: With the example of the Ming court's relationship with the fifth Karmapa and other Tibetan leaders, Norbu states that Chinese Communist historians have failed to realize the significance of the religious aspect of the Ming-Tibetan relationship. He writes that the meetings of lamas with the Emperor of China were exchanges of tribute between "the patron and the priest" and were not merely instances of a political subordinate paying tribute to a superior. He also notes that the items of tribute were Buddhist artifacts which symbolized "the religious nature of the relationship." Josef Kolmaš writes that the Ming dynasty did not exercise any direct political control over Tibet, content with their tribute relations that were "almost entirely of a religious character." Patricia Ann Berger writes that the Yongle Emperor's courting and granting of titles to lamas was his attempt to "resurrect the relationship between China and Tibet established earlier by the Yuan dynastic founder Khubilai Khan and his guru Phagpa." She also writes that the later Qing emperors and their Mongol associates viewed the Yongle Emperor's relationship with Tibet as "part of a chain of reincarnation that saw this Han Chinese emperor as yet another emanation of Manjusri."
Document 10: Sino-Tibetan relations during the Ming dynasty: Tibetan sources say Deshin Shekpa also persuaded the Yongle Emperor not to impose his military might on Tibet as the Mongols had previously done. Thinley writes that before the Karmapa returned to Tibet, the Yongle Emperor began planning to send a military force into Tibet to forcibly give the Karmapa authority over all the Tibetan Buddhist schools but Deshin Shekpa dissuaded him. However, Hok-Lam Chan states that "there is little evidence that this was ever the emperor's intention" and that evidence indicates that Deshin Skekpa was invited strictly for religious purposes.
Document 11: Sino-Tibetan relations during the Ming dynasty: Laird writes that the Ming appointed titles to eastern Tibetan princes, and that "these alliances with eastern Tibetan principalities are the evidence China now produces for its assertion that the Ming ruled Tibet," despite the fact that the Ming did not send an army to replace the Mongols after they left Tibet. Yiu Yung-chin states that the furthest western extent of the Ming dynasty's territory was Gansu, Sichuan, and Yunnan while "the Ming did not possess Tibet."
Document 12: Tibet: The language has numerous regional dialects which are generally not mutually intelligible. It is employed throughout the Tibetan plateau and Bhutan and is also spoken in parts of Nepal and northern India, such as Sikkim. In general, the dialects of central Tibet (including Lhasa), Kham, Amdo and some smaller nearby areas are considered Tibetan dialects. Other forms, particularly Dzongkha, Sikkimese, Sherpa, and Ladakhi, are considered by their speakers, largely for political reasons, to be separate languages. However, if the latter group of Tibetan-type languages are included in the calculation, then 'greater Tibetan' is spoken by approximately 6 million people across the Tibetan Plateau. Tibetan is also spoken by approximately 150,000 exile speakers who have fled from modern-day Tibet to India and other countries.
Document 13: Mount Everest: Mount Everest, known in Nepali as Sagarmatha (सगरमाथा) and in Tibetan as Chomolungma (ཇོ ་ མོ ་ གླང ་ མ), is Earth's highest mountain above sea level, located in the Mahalangur Himal sub-range of the Himalayas. The international border between Nepal (Province No. 1) and China (Tibet Autonomous Region) runs across its summit point.
Document 14: Tibet: Historically, the population of Tibet consisted of primarily ethnic Tibetans and some other ethnic groups. According to tradition the original ancestors of the Tibetan people, as represented by the six red bands in the Tibetan flag, are: the Se, Mu, Dong, Tong, Dru and Ra. Other traditional ethnic groups with significant population or with the majority of the ethnic group residing in Tibet (excluding a disputed area with India) include Bai people, Blang, Bonan, Dongxiang, Han, Hui people, Lhoba, Lisu people, Miao, Mongols, Monguor (Tu people), Menba (Monpa), Mosuo, Nakhi, Qiang, Nu people, Pumi, Salar, and Yi people.
Document 15: Sino-Tibetan relations during the Ming dynasty: Wang and Nyima argue that the Ming emperor sent edicts to Tibet twice in the second year of the Ming dynasty, and demonstrated that he viewed Tibet as a significant region to pacify by urging various Tibetan tribes to submit to the authority of the Ming court. They note that at the same time, the Mongol Prince Punala, who had inherited his position as ruler of areas of Tibet, went to Nanjing in 1371 to pay tribute and show his allegiance to the Ming court, bringing with him the seal of authority issued by the Yuan court. They also state that since successors of lamas granted the title of "prince" had to travel to the Ming court to renew this title, and since lamas called themselves princes, the Ming court therefore had "full sovereignty over Tibet." They state that the Ming dynasty, by issuing imperial edicts to invite ex-Yuan officials to the court for official positions in the early years of its founding, won submission from ex-Yuan religious and administrative leaders in the Tibetan areas, and thereby incorporated Tibetan areas into the rule of the Ming court. Thus, they conclude, the Ming court won the power to rule Tibetan areas formerly under the rule of the Yuan dynasty.
ground_truth: Mount Everest
sub_queries: Where did the Yongle Emperor send Yang Sanbao? Answer: Tibet
What is the highest elevation in Tibet ? Answer: Mount Everest