This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'True statement about Rt coronary aery (RCA) \nSelect and explain. \nA. Diameter less than LCA, B. RCA arises from anterior aoic sinus, C. RCA supplies major pa of right atrium and right ventricle, D. All', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Diameter less than LCA; B i.e. RCA arises from anterior aoic sinus', 'role': 'assistant'}]