Thomas sends his daughter Sophia to spend the summer with her grandparents, who eat dinner at 5:00 pm. Upon her return home, Sophia wants to eat dinner at 5:00 pm every night, even though she is not hungry and does not finish all the food on her plate. Sophia’s change in desired mealtime has most likely been influenced by ______.
a) drive reduction
b) classical conditioning
c) optimal arousal
d) low levels of the hormone ghrelin