This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Glands & Connective tissue, Subject name: Anatomy
[{'content': 'The mammary gland is which type of gland? \nSelect and explain. \nA. Apocrine, B. Merocrine, C. Holocrine, D. Endocrine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]