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.

Passage: A global drop in sea level at the end of the Devonian reversed early in the Carboniferous; this created the widespread epicontinental seas and carbonate deposition of the Mississippian. There was also a drop in south polar temperatures; southern Gondwana was glaciated throughout the period, though it is uncertain if the ice sheets were a holdover from the Devonian or not. These conditions apparently had little effect in the deep tropics, where lush coal swamps flourished within 30 degrees of the northernmost glaciers. A mid-Carboniferous drop in sea-level precipitated a major marine extinction, one that hit crinoids and ammonites especially hard. This sea-level drop and the associated unconformity in North America separate the Mississippian Period from the Pennsylvanian period.
What dropped world wide at the begining of the Devonian?

Passage: There is a sizeable Greek minority of about 105,000 (disputed, sources claim higher) people, in Albania. The Greek minority of Turkey, which numbered upwards of 200,000 people after the 1923 exchange, has now dwindled to a few thousand, after the 1955 Constantinople Pogrom and other state sponsored violence and discrimination. This effectively ended, though not entirely, the three-thousand-year-old presence of Hellenism in Asia Minor. There are smaller Greek minorities in the rest of the Balkan countries, the Levant and the Black Sea states, remnants of the Old Greek Diaspora (pre-19th century).
What other countries don't boast of a Greek populace?

Passage: The demographics of the British Isles today are characterised by a generally high density of population in England, which accounts for almost 80% of the total population of the islands. In elsewhere on Great Britain and on Ireland, high density of population is limited to areas around, or close to, a few large cities. The largest urban area by far is the Greater London Urban Area with 9 million inhabitants. Other major populations centres include Greater Manchester Urban Area (2.4 million), West Midlands conurbation (2.4 million), West Yorkshire Urban Area (1.6 million) in England, Greater Glasgow (1.2 million) in Scotland and Greater Dublin Area (1.1 million) in Ireland.[citation needed]
England accounts for almost 25% of the total population of where?