This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vestibulobullous disorders, Subject name: Dental
Toxic epidermal necrolysis {TEN} involves body surface area 
Select and explain. 
A. <10%, B. 10-20%, C. 20-30%, D. >30
D: >30
Answer: D: >30 
Explanation: Based on body surface area ( BSA) of skin involved, epidermal necrolysis is classified into SJS: less than 10% BSASJS_TEN overlap: 10-30% BSA TEN : more than 30% BSA. From illustrated synopsis of dermatology and sexually transmitted diseases neena khanna 5th edition page no 92