36 Question (1 point) v 1st attempt You are designing an experiment to test the effect of a new high blood pressure drug. You will have 1,000 participants divided into three groups: 300 people will be in a control group receiving a pill that has no active ingredient; 350 people will receive a low dose of the new drug: 350 people will receive a high dose of the new drug. Which variable(s) should be standard across all treatment groups? Choose one or more: O A the approximate age of the participants Q B. perfectly healthy blood pressure levels O C. the blood pressure measurement of all the participants during the experiment O D. the general state of health of all the participants O E. the amount of drug each participant in a test group receives