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: Private schools generally prefer to be called independent schools, because of their freedom to operate outside of government and local government control. Some of these are also known as public schools. Preparatory schools in the UK prepare pupils aged up to 13 years old to enter public schools. The name "public school" is based on the fact that the schools were open to pupils from anywhere, and not merely to those from a certain locality, and of any religion or occupation. According to The Good Schools Guide approximately 9 per cent of children being educated in the UK are doing so at fee-paying schools at GSCE level and 13 per cent at A-level.[citation needed] Many independent schools are single-sex (though this is becoming less common). Fees range from under 3,000 to 21,000 and above per year for day pupils, rising to 27,000+ per year for boarders. For details in Scotland, see "Meeting the Cost".
Output:
Who do preparatory schools in Scotland prepare to enter public schools?