Answer:
A: The subjects are the 100 patients who are being studied. The treatments are the amount and type of medicine they are getting, or whether they are getting a placebo. Lastly the response variable is the blood sauger in the patients at the end of the experiment.
B: The advantage of the random assignment of treatment is that it reduces the possibility of bias and ensures that the treatments are the only factors that effect the response variable.
C: Using a placebo when experimenting ensures that the treatments are actually the ones causing the change in the response variables, and that the treatments themselves are not using the placebo effect.
D: Using volunteers can cause voluntary response bias. This is when members of the population are allowed to volunteer for an experiment. This could cause the sample used by the experiment to not accurately reflect the population as a whole.
Step-by-step explanation:
I am not positive that these answers are correct, but I am reasonably sure.