Habitual Coffee Drinkers Often Experience an Almost Immediate Sense of Alertness

Habitual coffee drinkers often experience an almost immediate sense of alertness when they sip a fresh cup of coffee, even though it takes about 20 minutes for the caffeine in the coffee to reach significant levels in the bloodstream. What is the best explanation for this phenomenon?

A) After being repeatedly paired with the drug caffeine, the smell and taste of coffee have become a conditioned stimulus that elicits the conditioned response of alertness.
B) Negative reinforcement of a biologically prepared response is occurring.
C) Coffee drinking reinforces alertness on a fixed-ratio schedule of reinforcement.
D) The alertness is an example of the spontaneous recovery of a biologically prepared response.