The correct answer is option C, that is, one may become dehydrated because the kidneys will not hold onto enough water.
Hypothalamus monitors the functions like hunger, thirst, respiratory and cardiac function, and regulation of internal temperature. It also plays an essential function in the modifications of mood and emotions.
Thus, if hypothalamus is not functioning properly, then the mentioned functions of the gland may get hampered like the kidneys would not be able to hold enough water and may lead to dehydration.