In a Clinical Trial, 780 Participants Suffering from High Blood

In a clinical trial, 780 participants suffering from high blood pressure were randomly assigned to one of three groups. Over a one-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 diastolic blood pressure of each participant was measured at the beginning And at the end of the period and the change in blood pressure was recorded. Identify the levels of The factor.

A) Diastolic blood pressure at the start, diastolic blood pressure at the end
B) High blood pressure, low blood pressure
C) The experimental drug
D) Placebo, low dosage, high dosage