instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
Who married the woman who was to become Queen Beatrix of the Netherlands, on 10 March 1966?
answer:
beatrix


question:
Against which country did Britain fight 'The Cod Wars'?
answer:
cod wars


question:
In which films do the characters Peter Venkman, Ray Stantz, Egon Spengler and Winston Zeddemore appear?
answer:

egon spengler