In a recent study, sedentary middle-aged women who drank more than two cups of caffeinated tea a day were found more likely than other middle-aged women to have a high blood level of cholesterol, which is a factor increasing the risk of heart disease. Cholesterol can reach the blood from food and drink but is not contained in tea.
Which of the following, if true, most seriously weakness a conclusion from the study that for sedentary middle-aged women tea increases the risk of heart attack?
(A) A sedentary style of life increases levels of cholesterol in the blood.
(B) Tea contains caffeine, which acts as a stimulant that increases heart rate.
(C) The women studied drank their tea without milk or cream, which contain cholesterol.
(D) In both groups, the women were likely to be over-weight, and excess weight is a factor that increases the risk of heart disease.
(E) The women who drank more than two cups of tea a day also at more foods high in cholesterol.