Which is required for an ad to be served to a user?

Q: Which is required for an ad to be served to a user?

A) The keywords must be listed in all ad groups for a company.
B) The keywords must be relevant to the search term.
C) The keywords must be unique to only one campaign.
D) The search terms must be unique to a company.

Correct Answer is B) The keywords must be relevant to the search term.