Answer: The answer is crystallization
Explanation:
I attached the image related to your concerned question.
In theory, the part of the brain that is responsible for the sleep wake cycle is the hypothalamus; specifically, the ventrolateral preoptic nucleus of the hypothalamus. In the image, the location of the hypothalamus is pointed by the green square.
Adipose tissue is your answer
D) It can only be used in areas with specific kinds of rivers.
D. Lipids would be your answer