Which of the following statements is true?
a. Nutritional needs of healthy people vary during different life stages, such as infancy and pregnancy.
b. To achieve optimal health, you should individualize your diet to match your blood type, eye color, and other physical characteristics.
c. Regardless of their ages and physical conditions, people never need to take dietary supplements that include vitamins and minerals.
d. By taking dietary supplements that provide nutrients and phytochemicals, people can maintain good health without eating foods.