You are answering a USMLE-style medical question. Question: A 43-year-old woman presents with complaints of retrosternal burning associated with eating. It has persisted for the past several years but has been getting worse. Her past medical history is unknown and this is her first time seeing a doctor. She states she is otherwise healthy and review of systems is notable for episodic hand pain that is worse in the winter as well as a chronic and severe cough with dyspnea which she attributes to her smoking. Her temperature is 97.7°F (36.5°C), blood pressure is 174/104 mmHg, pulse is 80/min, respirations are 22/min, and oxygen saturation is 92% on room air. Physical exam is notable for a young appearing woman with coarse breath sounds. Laboratory studies and urinalysis are ordered and currently pending. Which of the following is the pathophysiology of this patient's chief complaint? Options: A) Decreased lower esophageal tone B) Esophageal fibrosis C) Increased lower esophageal tone D) Spastic cricopharyngeal muscle Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.