Final answer:
The subject of this question is Biology. It involves studying the effect of a drug for blood pressure on different groups of people. The experiment compares the blood pressure in a treatment group receiving the drug with a control group receiving a placebo to determine the drug's effectiveness.
Step-by-step explanation:
The subject of this question is Biology. The question is related to the effect of a drug for blood pressure on different groups of people. In this case, the experiment involves randomly assigning participants to either a treatment group receiving the drug or a control group receiving a placebo. The goal is to measure and compare the blood pressure in each group to determine the effectiveness of the drug.