<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 40-year-old man presents with substernal chest pain for the past hour. He describes the chest pain as severe, squeezing in nature, diffusely localized to the substernal area and radiating down his left arm. He also has associated nausea, dizziness, and diaphoresis. He denies any recent history of fever, chest trauma, palpitations, or syncope. Past medical history is significant for gastroesophageal reflux disease GERD, managed medically with a proton pump inhibitor for the last 3 months. He also has uncontrolled diabetes mellitus type 2 and hypercholesterolemia diagnosed 10 years ago. His last HbA1c was 8.0. The vital signs include: blood pressure 14090 mm Hg, pulse 100min, respiratory rate 20min, temperature 36.8C 98.3F and oxygen saturation 98 on room air. He is administered sublingual nitroglycerin which lessens his chest pain. Chest radiograph seems normal. Electrocardiogram ECG shows ST-segment elevation in anterolateral leads. Which of the following is the most likely diagnosis of this patient?? A: Acute coronary syndrome, B: GERD, C: Diffuse esophageal spasm, D: Pulmonary embolism, E: Pneumothorax,  <response>: Based on the description of severe substernal chest pain radiating to the left arm, associated with nausea, dizziness and diaphoresis, as well as a history of diabetes and hypercholesterolemia, the most likely diagnosis is acute coronary syndrome. The ECG showing ST elevation in anterolateral leads also points to this diagnosis. GERD is less likely given the severity and nature of the pain. Diffuse esophageal spasm, pulmonary embolism and pneumothorax do not fit the clinical presentation.A: Acute coronary syndrome 