Consider the following experiment, and identify the appropriate variables. 120 retriever puppies are divided into three groups of 40 puppies each. Each group is fed a different variety of puppy food: Miracle Puppy, Chowalicious, and Healthy Pups. The % weight gain of each puppy is measured after 3 months. Consider the following experiment, and identify the appropriate variables. 120 retriever puppies are divided into three groups of 40 puppies each. Each group is fed a different variety of puppy food: Miracle Puppy, Chowalicious, and Healthy Pups. The % weight gain of each puppy is measured after 3 months. The independent variable is the type of puppy food; the dependent variable is the breed of puppy used in the experiment. The independent variable is the type of puppy food; the dependent variable is % weight gain. The independent variable is the the size of the puppy's habitat; the dependent variable is % weight gain. The independent variable is the % weight gain; the dependent variable is the number of puppies in each group The independent variable is the number of puppies; the dependent variable is time