This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy of Skin, Subject name: Skin
Which of the following is not a component of sebum? 
Select and explain. 
A. Cholesterol, B. Wax, C. Glycerides, D. Propylene
D: Propylene
Answer: D: Propylene 
Explanation: Ans. (d) PropyleneRef: Rooks 8thed ch: 42.5