TASK DEFINITION: This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
PROBLEM: Passage: When revolutionary France declared war on Great Britain in 1793, the United States sought to remain neutral, but the Jay Treaty, which was favorable to Great Britain, angered the French government, which viewed it as a violation of the 1778 Treaty of Alliance. French privateers began to seize U.S. vessels, which led to an undeclared "Quasi-War" between the two nations. Fought at sea from 1798 to 1800, the United States won a string of victories in the Caribbean. George Washington was called out of retirement to head a "provisional army" in case of invasion by France, but President John Adams managed to negotiate a truce, in which France agreed to terminate the prior alliance and cease its attacks.

SOLUTION: What was the UK policy when France declared war on England in 1793?

PROBLEM: Passage: Uranium was also used in photographic chemicals (especially uranium nitrate as a toner), in lamp filaments for stage lighting bulbs, to improve the appearance of dentures, and in the leather and wood industries for stains and dyes. Uranium salts are mordants of silk or wool. Uranyl acetate and uranyl formate are used as electron-dense "stains" in transmission electron microscopy, to increase the contrast of biological specimens in ultrathin sections and in negative staining of viruses, isolated cell organelles and macromolecules.

SOLUTION: What product of uranium wasn't used as toner?

PROBLEM: Passage: Internal courtyards became more rare, except beside the stables, and the functional parts of the building were placed at the sides, or in separate buildings nearby hidden by trees. The views to and from the front and rear of the main block were concentrated on, with the side approaches usually much less important. The roof was typically invisible from the ground, though domes were sometimes visible in grander buildings. The roofline was generally clear of ornament except for a balustrade or the top of a pediment. Columns or pilasters, often topped by a pediment, were popular for ornament inside and out, and other ornament was generally geometrical or plant-based, rather than using the human figure.

SOLUTION:
What was often used too accentuate functional parts of buildings?