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: Medicine
[{'content': 'A patient presents with secondaries to the adrenals. The most common site of primary is - \nSelect and explain. \nA. Lung, B. Kidney, C. Breast, D. Stomach', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]