Research has shown that people are at increased risk for cancer a year or so after experiencing depression, helplessness, or grief. In describing this link, researchers are quick to point out that

a. accumulated stress causes cancer.

b. anger is the negative emotion most closely linked to cancer.

c. stress does not create cancer cells, but it weakens the body’s natural defenses against them.

d. feeling optimistic about chances of survival increases the likelihood of a cancer patient’s recovery.