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.

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 (U-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?
Sichuan and Qinghai

Passage: Originally known as Buckingham House, the building at the core of today's palace was a large townhouse built for the Duke of Buckingham in 1703 on a site that had been in private ownership for at least 150 years. It was acquired by King George III in 1761 as a private residence for Queen Charlotte and became known as "The Queen's House". During the 19th century it was enlarged, principally by architects John Nash and Edward Blore, who constructed three wings around a central courtyard. Buckingham Palace became the London residence of the British monarch on the accession of Queen Victoria in 1837. Question: Who was Buckingham Palace was originally built for?
Duke of Buckingham

Passage: Nontrinitarians, such as Unitarians, Christadelphians and Jehovah's Witnesses also acknowledge Mary as the biological mother of Jesus Christ, but do not recognise Marian titles such as "Mother of God" as these groups generally reject Christ's divinity. Since Nontrinitarian churches are typically also mortalist, the issue of praying to Mary, whom they would consider "asleep", awaiting resurrection, does not arise. Emanuel Swedenborg says God as he is in himself could not directly approach evil spirits to redeem those spirits without destroying them (Exodus 33:20, John 1:18), so God impregnated Mary, who gave Jesus Christ access to the evil heredity of the human race, which he could approach, redeem and save. Question: Which Nontrinitarian theologian says that God cannot approach eveil spirits to redeem them?
Emanuel Swedenborg