People with Low Levels of Education Have High Rates of Death

Multiple Choice

People with low levels of education have high rates of death from cardiovascular disease.The most valid explanation for this observation is that

A) low educational levels cause CVD.
B) high educational levels protect against CVD.
C) educational level is related to hypertension, obesity, and access to the health care system.
D) educational level is related to gender, which is related to amount of smoking, which is related to CVD.