Final answer:
Option (c), Infants maintain body temperature primarily through the breakdown of brown fat metabolism, a process known as nonshivering thermogenesis, which is particularly important as they cannot shiver as effectively as adults.
Step-by-step explanation:
Infants use a special form of thermoregulation known as nonshivering thermogenesis, which involves the breakdown of brown fat metabolism. Unlike the more common white fat, brown fat is specialized in generating heat and is found over the back, chest, and shoulders. This mechanism is crucial for infants because they are less capable of shivering, which is another way the body generates heat in response to cold.
Other mechanisms for regulating body temperature include shivering, sweating, the constriction or dilation of blood vessels, and altering behaviors such as seeking shade or curling up. In adults, a fever can induce chills and shivering as a way to combat infection and reset the body's thermostat back to normal. Infants, however, have a higher reliance on brown fat to maintain their body temperature.