Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

What is the title of the four-episode special of 'Doctor Who', made for the Red Nose Day telethon in the UK, broadcast in March 1999?
doctor who

Which American city has baseball-playing 'Dodgers'?
los angeles dodgers

Who was the voice of 'Charlie' in the TV series 'Charlie's Angels'?

charlie