This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Adrenal Gland, Subject name: Medicine
[{'content': 'The most common cause of malignant adrenal mass is: \nSelect and explain. \nA. Adrenocoical carcinoma, B. Malignant Phaeochromocytoma, C. Lymphoma, D. Metastasis from another solid tissue tumor', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Malignant Adrenocoical carcinoma 2-5 Malignant pheochromocytoma <1 Adrenal neuroblastoma <0.1 Lymphomas (including primary adrenal lymphoma) <1 Metastases (most frequent: breast, lung) 1-2', 'role': 'assistant'}]