This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2018, Subject name: Dental
A patient with acute history of blistering and denudation involving >30% BSA along with erosions of the lips with hemorrhagic crusting and other mucosa for few days. What is the most common triggering factor? 
Select and explain. 
A. Bacterial infection, B. Viral infection, C. Drug induced, D. Idiopathic
C: Drug induced
Answer: C: Drug induced 
Explanation: Lesions >30% BSA , erosion over lips and mucosa : Dx TEN TEN SJS: Haemorrhagic Crusting Sloughing of mucosa Targetoid lesion (2 rings) Nikolsky sign (Pseudo) due to epidermal necrosis. Epidermal necrosis (SJS/TEN) Etiology: Drugs: -Antiepileptic( MC) - CBZ, Lamotrigine * NSAIDS * Penicillin * Nevirapine CBZ induced SJS/TEN is a/w HLA B1502