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: The school has many nationally and internationally acclaimed scholars in social security, health care, health disparities, communication, social and health policy, and individual and family development. Many of the faculty have training in both social work and public health. The school's current dean is Edward F. Lawlor. In addition to affiliation with the university-wide Institute of Public Health, Brown houses 12 research centers. The Brown School Library collects materials on many topics, with specific emphasis on: children, youth, and families; gerontology; health; mental health; social and economic development; family therapy; and management. The library maintains subscriptions to over 450 academic journals.

SOLUTION: How many academic journal subscriptions does the Brown School Library have for mental health issues?

PROBLEM: Passage: The dominant land plant species of the time were gymnosperms, which are vascular, cone-bearing, non-flowering plants such as conifers that produce seeds without a coating. This is opposed to the earth's current flora, in which the dominant land plants in terms of number of species are angiosperms. One particular plant genus, Ginkgo, is thought to have evolved at this time and is represented today by a single species, Ginkgo biloba. As well, the extant genus Sequoia is believed to have evolved in the Mesozoic.

SOLUTION:
What plant species died out in the Mesozoic?