Researchers Exposed Some Participants to the Virus That Causes the Common

Researchers exposed some participants to the virus that causes the common cold and exposed other participants to an inert saline solution.They found that the more stress participants reported, the more likely they were to contract colds.Results of this study suggest that

A) stress can negatively affect our immune systems.
B) physical illness can make us more susceptible to stress.
C) exposure to viruses can be a source of stress on the immune system.
D) interpretations of stress are more important than objective stress.