Answer:
The answer is indeed group A.
Explanation:
In experimental design, participants are allocated to different conditions in order to find results. The experiment described in the question is, as a matter of fact, the most common type of allocation. The researcher divides the subjects into two groups, the control one and the experimental one. A change will be introduced only to the experimental group. Then, the results of both groups will be measured and compared to verify if the change has had any impact over the subjects.
Since the study in the question has the purpose of confirming if violence on TV influences children, the control group is the one that will not watch violent cartoons (group B). Their results will serve as comparison to the experimental group, which is introduced to the change - watching violent cartoons (group A).
