Cat body weight is a trait that shows continuous variation, as shown in the graph below of the body weights of a sample of 3 year old female male cats:
[Insert, the graph photo that is shown below, here]

Student 1 argued that continuous variation in cat body weight is caused by the effect of many genes all influencing the same trait in each individual cat.

Student 2 argued that continuous variation in cat body weight is caused by the effect of nutrition (an environmental factor) on the growth and development of each individual cat.

Given what you read above about polygenic inheritance and phenotypic plasticity, which of these explanations do you think is more likely for the continuous variation seen in cat body weight? Justify your answer with evidence from the graph.