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: On 24 August, Pravda and Izvestia carried news of the non-secret portions of the Pact, complete with the now infamous front-page picture of Molotov signing the treaty, with a smiling Stalin looking on. The news was met with utter shock and surprise by government leaders and media worldwide, most of whom were aware only of the British–French–Soviet negotiations that had taken place for months. The Molotov–Ribbentrop Pact was received with shock by Nazi Germany's allies, notably Japan, by the Comintern and foreign communist parties, and by Jewish communities all around the world. So, that day, German diplomat Hans von Herwarth, whose grandmother was Jewish, informed Guido Relli, an Italian diplomat, and American chargé d'affaires Charles Bohlen on the secret protocol regarding vital interests in the countries' allotted "spheres of influence", without revealing the annexation rights for "territorial and political rearrangement".

SOLUTION: Which diplomat never leaked information about the secret agreements?

PROBLEM: Passage: Contrary to the diffusionist theory, it appears that there was simultaneously a structural evolution towards the pointed arch, for the purpose of vaulting spaces of irregular plan, or to bring transverse vaults to the same height as diagonal vaults. This latter occurs at Durham Cathedral in the nave aisles in 1093. Pointed arches also occur extensively in Romanesque decorative blind arcading, where semi-circular arches overlap each other in a simple decorative pattern, and the points are accidental to the design.

SOLUTION: Which cathedral is the twisted arch used to match the heights of transverse and diagonal vaults?

PROBLEM: Passage: Prime numbers have influenced many artists and writers. The French composer Olivier Messiaen used prime numbers to create ametrical music through "natural phenomena". In works such as La Nativité du Seigneur (1935) and Quatre études de rythme (1949–50), he simultaneously employs motifs with lengths given by different prime numbers to create unpredictable rhythms: the primes 41, 43, 47 and 53 appear in the third étude, "Neumes rythmiques". According to Messiaen this way of composing was "inspired by the movements of nature, movements of free and unequal durations".

SOLUTION:
Which French composer wrote metrical music using prime numbers?