780 Men Suffering from High Blood Pressure Were Randomly Assigned

780 men suffering from high blood pressure were randomly assigned to one of three groups.Over a four-month period,the first group received a low dosage of an experimental drug,the second group received a high dosage of the drug,and the third group received a placebo.The biggest decrease in blood pressure was for those who received the low dosage of the drug.Identify the subjects studied.

A) The treatment received (placebo,low dosage,high dosage)
B) Change in diastolic blood pressure
C) The dosage of the drug
D) Adults suffering from high blood pressure
E) Men suffering from high blood pressure