Identify the confounding factor Exercise rightarrow Decrease

Identify the confounding factor: Exercise rightarrow Decreases LDL (bad cholesterol) rightarrow Decreases risk for heart disease There is no confounder because this is a causal chain. Exercise Risk for Heart Disease LDL (bad cholestrol)

Solution

It appears to me that d) LDL is the correct answer. This is because, LDL correlates to both exercise and decrease in heart disease