People hear a tone, followed by a puff of air to the eyes, which causes an eyeblink. After a few pairings, people blink their eyes when they hear the tone. What is the tone?

Which of the following statements is true?

a. Classical conditioning is an effective way to strengthen muscle tone. b. Classical conditioning is the associating of two things not normally associated with each other. c. Classical conditioning was once widely acknowledged, but has now been largely debunked. d. Classical conditioning is thought to be more powerful for altering behavior than operant conditioning.

Studies of biological factors affecting development of substance-use disorders implicate the neurotransmitter ____

a. dopamine b. adrenaline c. epinephrine d. acetylcholine