<h3>
Answer: B) Experiment</h3>
Reason:
Whenever you have two groups like this, one labeled the treatment group and the other the control group, we have an experiment gong on.
The treatment group gets the actual medication that is being tested. The control group gets a fake medication, aka placebo. Usually a placebo is meant for humans because it's more of a psychological factor. With cats, it likely won't affect them. However, such practices of having two groups like this is standard no matter what group of subjects you're testing.
The idea is that if the treatment group has better results compared to the placebo group, then it's likely the medication works.
Let the null hypothesis be that the agent's claim is correct. Using a standard normal probability table we find:

The p-value 0.14 is much larger than alpha = 0.01, so we cannot reject the agent's claim.
We can use pythagorean theorem:
a^2 + b^2 = c^2
4 + 9 = c^2
13 = c^2
sqrt of 13 = c
Hope this helps!
Be right there! Let's do this!