TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: What is the cathedral church of Rome?

SOLUTION: cathedral

PROBLEM: Who wrote '20,000 Leagues Under The Sea'?

SOLUTION: 20,000 leagues under the sea

PROBLEM: Who did Bulawayo born Charlene Wittstock marry earlier this month?

SOLUTION:
charlene, princess of monaco