TASK DEFINITION: This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
PROBLEM: Passage: The Tibetan Empire emerged in the 7th century, but with the fall of the empire the region soon divided into a variety of territories. The bulk of western and central Tibet (Ü-Tsang) was often at least nominally unified under a series of Tibetan governments in Lhasa, Shigatse, or nearby locations; these governments were at various times under Mongol and Chinese overlordship. The eastern regions of Kham and Amdo often maintained a more decentralized indigenous political structure, being divided among a number of small principalities and tribal groups, while also often falling more directly under Chinese rule after the Battle of Chamdo; most of this area was eventually incorporated into the Chinese provinces of Sichuan and Qinghai. The current borders of Tibet were generally established in the 18th century. Question: Which Chinese provinces used to be the eastern part of Tibet?

SOLUTION: Sichuan and Qinghai

PROBLEM: Passage: The Vedānta school built upon the teachings of the Upanishads and Brahma Sutras from the first millennium BCE and is the most developed and well-known of the Hindu schools. The epistemology of the Vedantins included, depending on the sub-school, five or six methods as proper and reliable means of gaining any form of knowledge: pratyakṣa (perception), anumāṇa (inference), upamāṇa (comparison and analogy), arthāpatti (postulation, derivation from circumstances), anupalabdi (non-perception, negative/cognitive proof) and śabda (word, testimony of past or present reliable experts). Each of these have been further categorized in terms of conditionality, completeness, confidence and possibility of error, by each sub-school of Vedanta. Question: Which is the most developed and well known of the Hindu schools?

SOLUTION: Vedānta

PROBLEM: Passage: The Japanese defenders recognized the possibility of a renewed invasion, and began construction of a great stone barrier around Hakata Bay in 1276. Completed in 1277, this wall stretched for 20 kilometers around the border of the bay. This would later serve as a strong defensive point against the Mongols. The Mongols attempted to settle matters in a diplomatic way from 1275 to 1279, but every envoy sent to Japan was executed. This set the stage for one of the most famous engagements in Japanese history. Question: How long was the Hakata Bay barrier?

SOLUTION:
20 kilometers