This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
[{'content': 'Which of the following are the features of phenytoin toxicity: \nSelect and explain. \nA. Gum hyperophy, B. Acne rosacea, C. Exacerbation of acne vulgaris, D. Loss of hair', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Gum hyperophy: Commonest ( more in younger age (b) Hirsutism, coarsening of facial fea :-..:: c (troublesome in young girls), acne. REF: KD TRIPATIH 8TH ED.', 'role': 'assistant'}]