A 24 years old (middle aged) female has flaccid bullae in the skin and persistent painful oral erosions (palatal & vestibular lesions in buccal mucosa). Histopathology shows intraepidermal acantholytic blister. The most likely diagnosis is
C i.e. Pemphigus vulgaris
Bullous Pemphigoid.
Erythema multiforme
Pemphigus vulgaris.
Dermatitis herpetiformis.