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
A 24 years old female has flaccid bullae in the skin and oral erosions. Histopathology shows intraepidermal acantholytic blister. The most likely diagnosis is – 
Select and explain. 
A. Pemphigoid, B. Erythema multiforme, C. Pemphigus vulgaris, D. Dermatitis herpetiformis
C: Pemphigus vulgaris
Answer: C: Pemphigus vulgaris 
Explanation: Flaccid bullae
Mucosa involved
Intraepidermal acantholysis