Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
--------
Question: Cinder Cone, composite, and shield are all types of what?

Answer: cinder cone


Question: What style of facial hair was famously worn by American Civil War general Ambrose Burnside?

Answer: ambrose burnside


Question: Who became US President Barack Obama's Vice President in 2008?

Answer:
barack obama