Classical conditioning applies mostly to operant conditioning applies mainly to biological responses; voluntary responses voluntary behavior; involuntary behavior voluntary behavior; biological behavior involuntary response; involuntary behavior

Classical conditioning is a type of learning in which a neutral stimulus comes to bring about a response after it is paired with a stimulus that naturally brings about that response. Operant conditioning is a type of learning in which a voluntary response is strengthened or weakened, depending on favorable or unfavorable consequences.
Classical conditioning applies mostly to involuntary behavior. Operant conditioning applies mainly to voluntary behavior. 

Idont know which one is right   but i know that c is wrong and a might be wrong