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 island experienced large-scale immigration over the 20th century, especially after the Second World War. Bermuda has a diverse population including both those with relatively deep roots in Bermuda extending back for centuries, and newer communities whose ancestry results from recent immigration, especially from Britain, North America, the West Indies, and the Portuguese Atlantic islands (especially the Azores), although these groups are steadily merging. About 46% of the population identified themselves with Bermudian ancestry in 2010, which was a decrease from the 51% who did so in the 2000 census. Those identifying with British ancestry dropped by 1% to 11% (although those born in Britain remain the largest non-native group at 3,942 persons). The number of people born in Canada declined by 13%. Those who reported West Indian ancestry were 13%. The number of people born in the West Indies actually increased by 538. A significant segment of the population is of Portuguese ancestry (10%), the result of immigration over the past 160 years, of whom 79% have residency status.

SOLUTION: During what century was the diverse immigration?

PROBLEM: Passage: Hitler's fierce anti-Soviet rhetoric was one of the reasons why the UK and France decided that Soviet participation in the 1938 Munich Conference regarding Czechoslovakia would be both dangerous and useless. The Munich Agreement that followed marked a partial German annexation of Czechoslovakia in late 1938 followed by its complete dissolution in March 1939, which as part of the appeasement of Germany conducted by Chamberlain's and Daladier's cabinets. This policy immediately raised the question of whether the Soviet Union could avoid being next on Hitler's list. The Soviet leadership believed that the West wanted to encourage German aggression in the East and that France and Britain might stay neutral in a war initiated by Germany, hoping that the warring states would wear each other out and put an end to both the Soviet Union and Nazi Germany.

SOLUTION: What countries helped the Soviets from joining the Munich Conference?

PROBLEM: Passage: In 1956, following the declaration of the Imre Nagy government of withdrawal of Hungary from the Warsaw Pact, Soviet troops entered the country and removed the government. Soviet forces crushed the nationwide revolt, leading to the death of an estimated 2,500 Hungarian citizens.

SOLUTION:
Which country withdrew from the Warsaw Pact in 1966?