Subepidermal bullae on trunk and flexural surface with linear C3/IgG basement membrane deposite are feature of –
Bullous pemphigoid shows :- 

Subepidermal bullae;
C3 and IgG linear band at denno - epidermal junction (Basement membrane).
Bullous pemphigoid
Pemphigus vulgaris
Linear Ig A disease
Dermatitis herpatifonnis