Which of the following does not describe a control group? O A. a group of patients given a new drug B. a group of patients given a placebo O C. a group of trees not given a new growth hormone O D. a group of students not given a new software package

The answer has to be A

Step-by-step explanation:

The trees have nothing changed about them, so they can be considered to be the control. In additon, placebo is given as a control in medical trials, so it cannot be correct. And, the students have nothing changed in D, so the answer to this question has to be A, where the patients are given a new drug.

my answer is$ 12

step-by-step explanation:

because 15 -2=12