In this task, you're given an ambiguous question (which can be answered in more than one way). Your task is to write a question that clarifies the given question in such a way that the generated question has one unique answer.

Who sang the song cotton fields back home?
Who sang the song cotton fields back home in 1940?

Where is the x factor final 2017 filmed?
In what building is the x factor final 2017 filmed?

Who has won the most soccer world cups?

Which country has won the most soccer world cups?