instruction:
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.
question:
What airline has its hub in charlotte nc?
answer:
What major airline has its hub in charlotte nc?


question:
When did the facebook messenger app come out?
answer:
When was the facebook messenger app originally developed as Facebook Chat?


question:
Who nominates judges to the us district courts?
answer:

Who officially nominates judges to the us district courts?