TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: The rivers Axe, Brue, Cary, Parrett, eta, are in which English county?

SOLUTION: castle cary

PROBLEM: Who composed 'Belshazzar's Feast' cantata?

SOLUTION: belshazzar's feast

PROBLEM: Alexander Graham Bell discovered that which type of cabling cancels out electrical interference?

SOLUTION:
alexander graham bell