Answer :
The subject is you and "you have" (not "you has" or "you hasn't"), so the answer is C. have.
Have you ever seen the Pacific Ocean?
Have you ever seen the Pacific Ocean?
C. have
because it make sense when you read it out loud
you is more than one therefore it isn't has or hasn't
because it make sense when you read it out loud
you is more than one therefore it isn't has or hasn't