This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'Base of the heart is formed by: \nSelect and explain. \nA. RA, B. RV, C. LA, D. LV', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. C LARef: BDC, 6th ed. vol. I pg. 253; Snell's Anatomy, pg. 137* Right ventricle is located between RA and LV. It doesn't form any boundary of heart* Right atrium forms the right border* Left atrium is located posteriorly. Forms the base of heart* Left ventricle forms the left border. Apex is formed by LV.", 'role': 'assistant'}]