One Factor That Makes a Food Aversion Different from Most

One factor that makes a food aversion different from most types of classical conditioning is that

A) other people can cause us to develop the connection the CS and the UCS.
B) once the conditioning is established, it cannot be eliminated.
C) the conditioned response often occurs before the unconditioned response.
D) there can be a long time delay between the CS and the UCS.
E) conditioning may not always involve a change in the person's response.