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: Oxygen was discovered independently by Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, and Joseph Priestley in Wiltshire, in 1774, but Priestley is often given priority because his work was published first. The name oxygen was coined in 1777 by Antoine Lavoisier, whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion. Its name derives from the Greek roots ὀξύς oxys, "acid", literally "sharp", referring to the sour taste of acids and -γενής -genes, "producer", literally "begetter", because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition. Common uses of oxygen includes the production cycle of steel, plastics and textiles, brazing, welding and cutting of steels and other metals, rocket propellant, in oxygen therapy and life support systems in aircraft, submarines, spaceflight and diving.

SOLUTION: When did Carl Priestly discover oxygen?

PROBLEM: Passage: Jews are often identified as belonging to one of two major groups: the Ashkenazim and the Sephardim. Ashkenazim, or "Germanics" (Ashkenaz meaning "Germany" in Hebrew), are so named denoting their German Jewish cultural and geographical origins, while Sephardim, or "Hispanics" (Sefarad meaning "Spain/Hispania" or "Iberia" in Hebrew), are so named denoting their Spanish/Portuguese Jewish cultural and geographic origins. The more common term in Israel for many of those broadly called Sephardim, is Mizrahim (lit. "Easterners", Mizrach being "East" in Hebrew), that is, in reference to the diverse collection of Middle Eastern and North African Jews who are often, as a group, referred to collectively as Sephardim (together with Sephardim proper) for liturgical reasons, although Mizrahi Jewish groups and Sephardi Jews proper are ethnically distinct.

SOLUTION: How many major groups do the Ashkenazim belong to?

PROBLEM: Passage: In February 2010, in response to controversies regarding claims in the Fourth Assessment Report, five climate scientists – all contributing or lead IPCC report authors – wrote in the journal Nature calling for changes to the IPCC. They suggested a range of new organizational options, from tightening the selection of lead authors and contributors, to dumping it in favor of a small permanent body, or even turning the whole climate science assessment process into a moderated "living" Wikipedia-IPCC. Other recommendations included that the panel employ a full-time staff and remove government oversight from its processes to avoid political interference.

SOLUTION:
What date was the Fourth Assessment Report published?