Megan wants to see if mice that are fed food A or B grow at a faster rate. She measures the mass of the mice on day 1, then divides them into two groups based on the type of food they will be given. She feeds each group the same amount of food at the same time each day. Does Megan have a control group in this experiment? A. No, there is no control group because she changes more than one variable. B. No, there is no control group because each group is treated under test conditions. C. Yes, the mice that are fed food A are the control group, and those that are fed food B are the test group. D. Yes, the mice that are fed food B are the control group, and those that are fed food A are the test group.

The experimental group is the group in which the variable to be tested is provided to see the effect whereas control group is the group in which the variable to be studied is not provided and the sample is kept in the natural condition.

In the given condition, since Megan divided the samples into two groups provided sample A and B but forgot to add a sample to control group, where no variable to be studied, is given instead of which some other type of food is given in the same amount and at the same time. This control group would help compare the experimental samples.

Thus, Option-B is the correct answer.