The correct answer is - increasing the rate of cellular respiration in the mitochondria.
Explanation:
During the infection, the body of mammals increases its temperature to kill the pathogens that normally die at high temperatures. To increase the body temperature our body promotes the rate of cellular respiration in the cells to produce more energy.
Cellular respiration is the process that helps in converting stored energy into a form of useable energy for the cell which is ATP. It takes place in the mitochondria of the cell which is called as the powerhouse of the cell and all the function related to energy or ATP is conducted by here.