Read the Following Scenario and Answer the Question Below

Read the following scenario and answer the question below.
Pablo and Johanna have to do a yearlong study for their biology course. After some discussion, they decide to try comparing their dogs and the diet that they feed them to test their hypothesis that the local veterinarian's special dog food mix will enhance growth and development. Each student adopts a puppy from the local pound. Pablo plans to feed his shepherd- mix dog the special diet, while Johanna plans to use generic dry kibble from the supermarket for her bulldog.
-Pablo and Johanna have too many _________

A) controlled variables and not enough uncontrolled variables
B) replicates and not enough variables
C) independent variables and not enough dependent variables
D) variables that they didn't control and not enough replicates
E) dependent variables and not enough independent variables