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
The term erythroderma is applied when any inflammatory skin disease affects more than ___ of body surface area 
Select and explain. 
A. 70%, B. 80%, C. 90%, D. 100%
C: 90%
Answer: C: 90% 
Explanation: Erythroderma is involvement of more than 90% of skin in any disorder.