You will be given a definition of a task first, then some input of the task.
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: As well as being head of government, a prime minister may have other roles or titlesthe Prime Minister of the United Kingdom, for example, is also First Lord of the Treasury and Minister for the Civil Service. Prime ministers may take other ministerial postsfor example, during the Second World War, Winston Churchill was also Minister of Defence (although there was then no Ministry of Defence), and in the current cabinet of Israel, Benjamin Netanyahu also serves as Minister of Communications, Foreign Affairs, Regional Cooperation, Economy and Interior
Output:
What are former titles once held by the Prime Minister of the UK?