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

[EX Q]: In which war did the Sack of Badajoz takeplace?
[EX A]: siege of badajoz

[EX Q]: Who was in the films Zelig, Stardust Memories, and Broadway Danny Rose?
[EX A]: broadway danny rose

[EX Q]: Which word beginning with 'o' is the branch of medical science that deals with pregnancy and childbirth?
[EX A]:
childbirth