human
temperature=0.000000
Question:A 79-year-old man presents to the office due to shortness of breath with moderate exertion and a slightly productive cough. He has a medical history of 25 years of heavy smoking. His vitals include: heart rate 89/min, respiratory rate 27/min, and blood pressure 120/90 mm Hg. The physical exam shows increased resonance to percussion, decreased breath sounds, and crackles at the lung base. Chest radiography shows signs of pulmonary hyperinflation. Spirometry shows a forced expiratory volume in the first second (FEV1) of 48%, a forced vital capacity (FVC) of 85%, and an FEV1/FVC ratio of 56%. According to these results, what is the most likely diagnosis?
Options: (A Asthma (B Lymphangioleiomyomatosis (C Chronic obstructive pulmonary disease (COPD) (D Heart failure

Explanation: Let’s solve this step-by-step, referring to authoritative sources as needed. The patient’s history of smoking, physical examination findings of decreased breath sounds and crackles at the lung base, and spirometry results of a low FEV1/FVC ratio suggest Chronic obstructive pulmonary disease (COPD). Asthma will have a higher FEV1/FVC ratio. Lymphangioleiomyomatosis will have a normal FEV1/FVC ratio. Heart failure will have a low FEV1/FVC ratio but the patient’s vital signs are not consistent with heart failure.
Answer: (C Chronic obstructive pulmonary disease (COPD)
Instruction:Above is a medical question and a student-written answer, and I need you to help me extract the answer and output a single option from the four options.All you need to do is extracting the answer correctly(No matter the student's answer is right or not) and just give me the letter.The format of your answer must be:
Answer : X
X represents one of the four capital letters A, B, C, D.I just want the letter without what the option actual is.You don't need to answer what the option actual is.Just give me the captital letter
gpt
--- Reasoning ---
1. Is the question multiple-choice question?
Yes

--- Answer ---
grounded