The Authors of Your Text Provide a "Word of Caution

The authors of your text provide a "word of caution." It can be dangerous to overestimate the relation between perceived control and physical health,because

A) scientists still do not understand the mechanisms that explain this relation.
B) when health problems improve, people lose a sense of perceived control.
C) currently all the evidence is correlational.
D) when people's health does not improve with treatment, they may blame themselves.
E) it is impossible to determine whether perceived control and health are causally related.