One of the prominent mid-term symptoms of stress is that a person is likely to develop a cold. Why does this happen?
O A. The immune system was temporarily decreased during the time period he/she was experiencing stress.
O B. The digestive system was temporarily increased during the time period he/she was experiencing stress.
O C. The immune system was temporarily increased during the time period he/she was experiencing stress.
O D. The digestive system was temporarily decreased during the time period he/she was experiencing stress.