Answer:
Group A is the control of the experiment
Explanation:
In an experiment, the control group is the group that does not receive any experimental treatment. The control groups are kept in the same condition as the experimental group except the variable being tested (independent variable).
In this question involving an experiment to determine the effects of antibiotics on the treatment of pneumonia in mice. Two groups of mice were employed. One of the groups (group A) received no antibiotic while the other group (group B) received 10 mg/kg of antibiotics. This means that GROUP A is the CONTROL GROUP of this experiment.