A client is admitted to a medical unit with a diagnosis of gastritis and chronic heavy alcohol abuse. Which medication should the nurse administer to prevent the development of Wernicke's syndrome?

A. Lorazepam is not indicated for preventing Wernicke's syndrome. B. Famotidine is a histamine-2 blocker used to reduce stomach acid secretion and treat gastritis symptoms but does not prevent Wernicke's syndrome. C. Atenolol is a beta-blocker used to treat hypertension and angina, not to prevent Wernicke's syndrome. D. Thiamine supplementation is essential in individuals with chronic alcohol abuse to prevent Wernicke's syndrome, which is caused by thiamine deficiency.