Research Findings on Stress and Illness Indicate That There Is

Research findings on stress and illness indicate that there is a

A) lack of association between stress and illness; contrary to researchers' hypotheses.
B) correlation between stress and illness; the causal direction is not known.
C) causal relationship between stress and illness; physical symptoms result in stressful life events.
D) causal relationship between stress and illness; stressful life events cause physical symptoms.