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: The French population numbered about 75,000 and was heavily concentrated along the St. Lawrence River valley, with some also in Acadia (present-day New Brunswick and parts of Nova Scotia, including Île Royale (present-day Cape Breton Island)). Fewer lived in New Orleans, Biloxi, Mississippi, Mobile, Alabama and small settlements in the Illinois Country, hugging the east side of the Mississippi River and its tributaries. French fur traders and trappers traveled throughout the St. Lawrence and Mississippi watersheds, did business with local tribes, and often married Indian women. Traders married daughters of chiefs, creating high-ranking unions.

SOLUTION: What wasn't the French population in North America?

PROBLEM: Passage: As heirs of the Dominican priory of Poissy in France, the Dartford sisters were also heirs to a tradition of profound learning and piety. Sections of translations of spiritual writings in Dartford's library, such as Suso's Little Book of Eternal Wisdom and Laurent du Bois' Somme le Roi, show that the "ghoostli" link to Europe was not lost in the crossing of the Channel. It survived in the minds of the nuns. Also, the nuns shared a unique identity with Poissy as a religious house founded by a royal house. The English nuns were proud of this heritage, and aware that many of them shared in England's great history as members of the noble class, as seen in the next chapter.

SOLUTION: What priory were the Dartford sisters not heirs to?

PROBLEM: Passage: The most basic method of checking the primality of a given integer n is called trial division. This routine consists of dividing n by each integer m that is greater than 1 and less than or equal to the square root of n. If the result of any of these divisions is an integer, then n is not a prime, otherwise it is a prime. Indeed, if  is composite (with a and b ≠ 1) then one of the factors a or b is necessarily at most . For example, for , the trial divisions are by m = 2, 3, 4, 5, and 6. None of these numbers divides 37, so 37 is prime. This routine can be implemented more efficiently if a complete list of primes up to  is known—then trial divisions need to be checked only for those m that are prime. For example, to check the primality of 37, only three divisions are necessary (m = 2, 3, and 5), given that 4 and 6 are composite.

SOLUTION:
What is the most elemental way to test the primality of any division?