You are answering a USMLE-style medical question. Question: A 65-year-old man presents to his primary care physician for a change in his behavior over the past few months. Initially, the patient was noted to be behaving inappropriately including using foul language and grabbing people unexpectedly. This has progressed to a worsening of his memory and trouble caring for himself. His temperature is 98.1°F (36.7°C), blood pressure is 162/103 mmHg, pulse is 83/min, respirations are 13/min, and oxygen saturation is 98% on room air. Physical exam is notable for an elderly man who laughs inappropriately at times and who is a poor historian. When he is engaged in conversation, he exhibits word finding difficulty and is rather inattentive. Which of the following is the most likely diagnosis? Options: A) Alzheimer dementia B) Frontotemporal dementia C) Kluver-Bucy syndrome D) Vascular dementia Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.