instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
Name the town in California where Clint Eastwood was elected mayor in 1986.?
answer:
clint eastwood

question:
Princess Estelle, Duchess of Ostergotland, granddaughter to King Carl XVI Gustaf, became 2nd in line to what nation's throne when born in 2012?
answer:
carl xvi gustaf of sweden

question:
The main mouth of the Amazon lies in which country?
answer:
amazon