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: Skin
[{'content': 'Which of the following is an agent used for deep chemical peels? \nSelect and explain. \nA. Carbolic acid, B. Glycolic acid, C. Mandelic acid, D. Salicylic acid', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Carbolic acid / phenol is used for deep peels & is a component of Baker - Gordon formula. All others are hydroxy acids used for superficial & medium depth peels. Ref: Textbook of dermatosurgery & cosmetology, Satish S savant, E-2, P-177.', 'role': 'assistant'}]