This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Dental
A girl about to marry has comedonal acne. Drug to treat such a case is: 
Select and explain. 
A. Topical antibiotic, B. Benzoyl peroxide, C. Retinoids, D. Estrogen
C: Retinoids
Answer: C: Retinoids 
Explanation: Retinoids are mainly comedolytic Acne Comedones are characteristic of: Acne vulgaris Comedones are: * Small cysts, * formed in hair follicles, * due to blockage of the follicular orifice * by the retention of sebum and keratinous material. Ref : Ref : Thomas b Habif 6th Ed.