Investigating the Relationship Between Stress and Susceptibility to the Common

Investigating the relationship between stress and susceptibility to the common cold, psychologist Sheldon Cohen and his colleagues found that:

A) it is a myth that stress is associated with greater susceptibility to the common cold and respiratory infections.
B) when people are under chronic or long-term stress, their immune system functioning responds strongly, reducing susceptibility to the common cold and other infections.
C) the higher a person's level of stress, the higher the rate of respiratory infections and colds.
D) those with a pessimistic explanatory style are more susceptible to the common cold than those with an optimistic explanatory style.