Review Question - QID 216755

A 72-year-old man is brought into clinic by his son who is becoming more concerned about his father's ability to care for himself. Initially, the patient's son noticed the patient was more forgetful with tasks such as paying bills several years ago. This has slowly progressed to the patient occasionally wandering the streets alone unsure of how to return home. His past medical history includes hypertension, diabetes, and hyperlipidemia. He is a former smoker and drinks alcohol on special occasions only. His temperature is 97.5°F (36.4°C), blood pressure is 139/88 mmHg, pulse is 75/min, respirations are 13/min, and oxygen saturation is 97% on room air. He is pleasantly conversant and when asked whether he has had worsening memory loss, he denies any concerns. He reports that he feels healthy and is unsure why he's seeing a doctor. He denies any numbness or tingling in his extremities and has a normal gait. He scores 17 on the Montreal Cognitive Assessment. Which of the following is the most likely diagnosis?