Problem: Diana works as a health-care professional in Redwood Nursing Home. Which of the following instructions should she give her patients when they are taking their nutritional supplements? Select one: a. Always take nutritional supplements on an empty stomach. b. Chew extended-release formulations of vitamins. c. Brief periodic exposure to sunlight is essential for maintaining a normal level of vitamin D. d. It is imperative to notify the physician of any changes in the color of urine while taking riboflavin.