Answer: The answer is a. hunger.
Step-by-step explanation:
Hypothalamus is a ventral part of diencephalon. It has many functions including control of hunger, thirst, body temperature, sleep, parenting behaviors, and circadian rhythms.
When an animal is not hungry, and it needs for food are satisfied, is called satiety. There is satiety center responsible for hunger. The center is located in hypothalamus.