Answer:
The correct answer is letter "A": A hypothesis.
Step-by-step explanation:
A Hypothesis is an idea on a certain specified topic that is proved to be true by testing it through study and experimentation. Actually, that idea must be tested many times before it can be labeled as a theory. In the example, Catherine hypothesis is:
Viewing particular television programs has an impact on behavior.
She plans to test her idea by studying children's prone to aggressiveness after being exposed to violent television shows.