Studying dogs as a model system for obesity | Quick Homework Help

Suppose you are interested in studying dogs as a system for obesity. You crossed a Cocker Spaniel to a Labrador Retriever and interbred the offspring for several generations. All of the dogs are given access to the same amount of food and raised on the same farm. You examine dogs in the fourth generation of your breeding program and measure their weight gain as pounds per day over a fixed period of time. You graph the data for a large number of dogs and find a continuous distribution for the weight gain. Which of the following statements support your data ( select all that are true).
a) Rate of weight gain in dogs is affected by environmental factors.
b) There are probably only 1 or 2 genetic factors controlling obesity in dogs.
c) Obesity in dogs is controlled by several genetic factors.
d) Obesity in dogs is not measurably affected by environmental factors.