This is an amazing quiz and I love it, however there are a few things that you could improve to make it even better:
--Maybe categorize the characters by which Doctor (or Doctors) meets them or by what species they are
--Make "Amelia" acceptable as well as "Amy"
--Get rid of some of the characters (if it's possible) because there are some that I might not get even if I saw the episode that they're in
Overall, though, your quiz is really great and keep creating!