Abe constantly worries about his hands being dirty, and germs leading to an infection. He washes his hands to the point where his skin is chafing, but still worries that his hands are not clean enough. He also carries around alcohol wipes to clean his hands in his car, due to distress over the possibility of germs. He simply feels that his hands are never, ever clean enough. Abe's thoughts are typical of a(n) ________.
a. hallucination
b. obsession
c. compulsion
d. delusion