A factory worker who gets paid $50 for every 100 carburetors he assembles is reinforced

Freud believed that ________ are the "royal road to the unconscious."

Fill in the blank(s) with the appropriate word(s).

______ reinforcers result in the learning of new behaviors or the strengthening of existing ones

a. Neither positive nor negative c. Negative, but not positive b. Positive, but not negative d. Positive and negative