Correct Option: D

The body keeps its core temperature constant at about 37 C by physiological adjustments controlled by the hypothalamus (Thermostat Center) where there are neurons sensitive to changes in skin and blood temperatures. The temperature-regulating centers are found in the Preoptic Area (the anterior portion of the hypothalamus). This area receives input from temperature receptors in the skin and mucous membranes (Peripheral Thermoreceptors) and from internal structures (Central Thermoreceptors), which include the hypothalamus itself. The temperature sensory signals from the preoptic area and those form the periphery are combined in the posterior hypothalamus to control the heat producing and conserving reactions of the body. The hypothalamic thermostat works in conjunction with other hypothalamic, autonomic and higher nervous thermoregulatory centers to keep the core temperature constant.