Which of the following has the highest amount of caffeine per serving?

When Ann went to her doctor, he gave her a hearing test. He presented her tones through earphones. The tones started at a low intensity and then became louder. The doctor asked Ann to raise her hand whenever she started to hear a sound. Ann's _______ was being tested.

a. auditory convergence b. absolute threshold c. refractory threshold d. difference threshold

_____ is any event or object in the environment to which an organism responds

a) Higher-order conditioning b) Negative reinforcement c) Shaping d) A stimulus