Answer:
The correct option is: B. hypothalamus
Explanation:
Hypothalamus is a structure present in the brain of the vertebrates. It is a vital part of the nervous system that connects the nervous system and the endocrine system and is responsible for producing and secreting neurohormones.
It is also responsible for regulating the body temperature, appetite, sexual behavior, sleep, fatigue, emotional responses and thirst.
In the given example, the symptoms experienced by Elaina most likely suggests that the brain tumor is affected the hypothalamus.