TASK DEFINITION: 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.
PROBLEM: Who is the highest ranked golfer in the world?

SOLUTION: Who is the highest ranked golfer in the world on February 19, 2017?

PROBLEM: Who were the first european to reach the americas and when did they arrive?

SOLUTION: Who were the first Europeans to reach the Americas?

PROBLEM: Where did the we can do it poster come from?

SOLUTION:
What time period did the we can do it poster come from?