TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Dora Maar au Chat and The Weeping Woman are both portraits by which artist of his lover?

SOLUTION: dora maar au chat

PROBLEM: Field Marshal Arthur Wellesley, shares his better known title with which Southern Hemisphere capital city?

SOLUTION: arthur wellesley, 1st duke of wellington

PROBLEM: Which is the only Avril Lavigne song to have reached No.1 in the US Billboard Chart?

SOLUTION:
avril lavigne