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: Dental
A 24 year old unmarried woman has multiple nodular, cystic, pustular and comadonic lesions on face, upper back and shoulders for 2 years. The drug of choice for her treatment would be – 
Select and explain. 
A. Acitretin, B. Isotretinoin, C. Doxycycline, D. Azithromycin
B: Isotretinoin
Answer: B: Isotretinoin 
Explanation: The DOC for nodulocystic acne is oral isotretinoin (13-Cis Retinoic acid)
Indications of isotretinoin →   Severe acne (>25 lesions), Nodulocystic lesions, Large nodular lesions, Moderate acne not responding to oral antibiotics (Recalcitrant acne).