In Studying the Relationship Between Stress and Susceptibility to the Common

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

A) when they are exposed to a cold virus, people who are under chronic stress are much more likely to develop colds than people who are not under chronic stress.
B) there was no relationship between chronic stress, exposure to a cold virus, and developing a cold.
C) decreased levels of corticosteroids in the highly stressed participants boosted their immune systems' response to the cold virus.
D) when they are exposed to a cold virus, people who are under chronic stress are much less likely to develop colds than people who are not under chronic stress.