Which Example Most Clearly Shows That an Animal's Biological Predispositions

Multiple Choice

Which example most clearly shows that an animal's biological predispositions can affect the ease of learning an association

A)  Garcia's rats drinking sweet water that had been paired with shock 
B)  Skinner's rats pressing levers in an operant chamber 
C)  Pavlov's dogs learning to salivate to a tone 
D)  Thorndike's cats escaping a puzzle box