**Core Concept**
The patient's presentation of tense bullae on an erythematous base is suggestive of a blistering disorder, specifically bullous pemphigoid. This condition is characterized by the formation of autoantibodies against components of the basement membrane zone, leading to the separation of the epidermis from the dermis.

**Why the Correct Answer is Right**
Bullous pemphigoid is an autoimmune disease where autoantibodies target the hemidesmosomal proteins BP230 and BP180, leading to the activation of complement and the recruitment of neutrophils and eosinophils. This results in the formation of tense bullae on an erythematous base. The histopathological examination would reveal a subepidermal blister with a mixed inflammatory infiltrate, including eosinophils, neutrophils, and lymphocytes.

**Why Each Wrong Option is Incorrect**
**Option A:** This option might be incorrect because it does not correctly identify the characteristic histopathological features of bullous pemphigoid.
**Option B:** This option might be incorrect because it is more characteristic of pemphigus vulgaris, which typically presents with flaccid bullae and a suprabasal split.
**Option C:** This option might be incorrect because it is more characteristic of dermatitis herpetiformis, which typically presents with itchy, blistering skin and a granular IgA deposit in the dermal papillae.

**Clinical Pearl / High-Yield Fact**
Bullous pemphigoid is often associated with autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus, and patients may also have a history of atopy or allergies.

**Correct Answer: B. Subepidermal blister with a mixed inflammatory infiltrate, including eosinophils, neutrophils, and lymphocytes.**