The correct option is C Hypothalamus
The hormones produced by hypothalamus control body temperature, thirst, hunger, sleep, circadian rhythm, moods, sex drive, and the release of other hormones in the body. The hunger and satiety centre, the thermoregulatory centre is present in the hypothalamus. So, a tumor in that region may cause the abnormalities, as low body temperature, loss of appetite and extreme thirst.