A 19-year-old Hispanic man with a body mass index of 32 kg/m2 presents to your office with a complaint of darkened skin. Physical exam reveals thickened, velvety, darkly pigmented plaques on the back of his neck. Which of the following is the most appropriate next step in management?a. Referral to gastroenterology
b. Screening for diabetes mellitus
c. Skin biopsy
d. Trial of topical retinoids
