Multiple choice: Select the best answer for Exercises 87 to 94. Can changing diet reduce

QUESTION:

Multiple choice: Select the best answer for Exercises 87 to 94. Can changing diet reduce high blood pressure? Vegetarian diets and low-salt diets are both promising. Men with high blood pressure are assigned at random to four diets: (1) normal diet with unrestricted salt; (2) vegetarian with unrestricted salt; (3) normal with restricted salt; and (4) vegetarian with restricted salt. This experiment has (a) one factor, the type of diet. (b) two factors, high blood pressure and type of diet. (c) two factors, normal/vegetarian diet and unrestricted/ restricted salt. (d) three factors, men, high blood pressure, and type of diet. (e) four factors, the four diets being compared.