This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Acne, Subject name: Skin
Comedons are characteristics of: 
Select and explain. 
A. Acne vulgaris, B. Acne rosasea, C. SLE, D. d. Adenoma sebaceum
A: Acne vulgaris
Answer: A: Acne vulgaris 
Explanation: Ans is 'a' i.e, Acne vulgaris