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

The counties of Alameda, El Dorado, Fresno, Marin, Mariposa, Nevada, Orange, Riverside, Sacramento, San Bernardino, San Joaquin, San Mateo, Santa Clara, Santa Cruz, Sonoma and Ventura are in what state of the USA?
santa clara, california

Charon is a moon which orbits which body?
charon

Which breed of dog is Marley in the 2008 film 'Marley and Me'?

dog