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

In 2012 , who became the first woman writer to win the Booker Prize for the second time ?
man booker prize

The Costa Smeralda (or Emerald Coast) is a feature of which Mediterranean island?

mediterranean sea