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.

[EX Q]: Passage: The principles of imperialism are often generalizable to the policies and practices of the British Empire "during the last generation, and proceeds rather by diagnosis than by historical description". British imperialism often used the concept of Terra nullius (Latin expression which stems from Roman law meaning 'empty land'). The country of Australia serves as a case study in relation to British settlement and colonial rule of the continent in the eighteenth century, as it was premised on terra nullius, and its settlers considered it unused by its sparse Aboriginal inhabitants.
[EX A]:  Imperialism is less often associated with which sovereignty?

[EX Q]: Passage: The most precise timekeeping device of the ancient world was the water clock, or clepsydra, one of which was found in the tomb of Egyptian pharaoh Amenhotep I (1525–1504 BC). They could be used to measure the hours even at night, but required manual upkeep to replenish the flow of water. The Ancient Greeks and the people from Chaldea (southeastern Mesopotamia) regularly maintained timekeeping records as an essential part of their astronomical observations. Arab inventors and engineers in particular made improvements on the use of water clocks up to the Middle Ages. In the 11th century, Chinese inventors and engineers invented the first mechanical clocks driven by an escapement mechanism.
[EX A]: What device was invented by the ancient Greeks?

[EX Q]: Passage: Juscelino Kubitschek, President of Brazil from 1956 to 1961, ordered the construction of Brasília, fulfilling the promise of the Constitution and his own political campaign promise. Building Brasília was part of Juscelino's "fifty years of prosperity in five" plan. Lúcio Costa won a contest and was the main urban planner in 1957, with 5550 people competing. Oscar Niemeyer, a close friend, was the chief architect of most public buildings and Roberto Burle Marx was the landscape designer. Brasília was built in 41 months, from 1956 to April 21, 1960, when it was officially inaugurated.
[EX A]:
During what time period was Lucio Costa President of Brazil?