The american cancer society suggests that in order to prevent cancer, a diet should be rich in:
a. red meat, eggs, and dairy
b. bread, rice, and cereal
c. legumes, soy milk, and tofu
d. a variety of plant based foods

d. A variety of plant based foods

Explanation:

The important cancer risk factors for most Americans which are not using tobacco can be changed are body weight and diet.World Cancer Research   Fund estimates that 20% approximately of all the cancers diagnosed in US are related to the body  fatness, the physical inactivity, poor nutrition and excess of alcohol consumption.

Avoiding tobacco products,  staying active, and eating healthy diet may  reduce person's lifetime risk of cancer. The society suggests that a healthy diet which includes a lot of plant foods can help to prevent cancer.