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
Which of the following is a holocrine gland: 
Select and explain. 
A. Sweat gland, B. Breast, C. Pancrea, D. Sebaceous gland
D: Sebaceous gland
Answer: D: Sebaceous gland 
Explanation: Sebaceous gland is a holocrine gland since the discharged secretion contains entire secreting cells. Sweat glands are of two types: Eccrine (merocrine) is more common in occurence as compared to apocrine variety. Breast (mammary gland) is modified sweat gland of apocrine variety. Another example for similar type is ceruminous (wax) gland in the ear. Pancreas is a mixed (exocrine & endocrine) gland. Exocrine secretory units are usually merocrine type.