Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

[Q]: What's missing: Magnum Force, The Enforcer, Sudden Impact, and The Dead Pool?
[A]: sudden impact


[Q]: Eden Park staged some of the 2011 Rugby World Cup matches, in which city can it be found?
[A]: eden park


[Q]: By what name is Brian Warner better known as in the music world?
[A]:
brian warner