Tomas really likes chocolate. Every time he eats a piece of chocolate, he gets a warm and fuzzy feeling. Lately, he has noticed that he gets that feeling whenever he enters the candy store to buy some chocolate. Now he really likes the candy store. For Tomas, the warm and fuzzy feeling he gets when he enters the store is a(n)
A) CR
B) discriminative stimulus
C) UCS
D) CS
E) UCR