You are answering a USMLE-style medical question. Question: A 71-year-old woman presents to her physician accompanied by her son. She has no complaints, but her son states that the patient has impaired memory and poor orientation in space. She is ambulatory and is capable of self-care, but she tends to forget newly introduced information. Also, she got lost on the way from the home to the local market several times for the past 6 months, and her family is now afraid to let her go anywhere on her own. She does not have any concomitant chronic conditions nor did she have major cardiovascular events or head trauma. It is known that her father had dementia. The vital signs include: blood pressure is 130/80 mm Hg, heart rate is 62/min, respiratory rate is 11/min, and the temperature is 36.5°C (97.7°F). The respiratory, cardiologic, and abdominal examinations are unremarkable. The neurological examination shows equal, round pupils with a normal reaction to light. The eye movements are normal with no nystagmus and normal oculocephalic reflex. There is no facial droop, the facial sensation is preserved, and there is no tongue deviation noted. There is no motor or sensory deficits on the upper and lower extremities. The patient scores 18 on the Montreal Cognitive Assessment. Which of the following medications is indicated in the patient? Options: A) Imipramine B) Lithium C) Donepezil D) Sulpiride Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.