A Researcher Is Interested in the Effects of a Vegetarian

A researcher is interested in the effects of a vegetarian diet on memory. One group eats a strict vegetarian diet for three months, a second group eats a strict vegan diet for three months, while a third group eats anything they want for three months. After three
Months, all participants are given a memory test. Results indicated that memory was better for both the vegetarian and vegan groups. In this study, the dependent variable is

A) the vegetarian diet
B) scores on the memory test
C) the vegan diet
D) the type of diet
E) not enough information to tell