**Core Concept**
Blisters in burns are a result of the body's attempt to protect the damaged area from further injury. In superficial 2nd degree burns, the epidermis and a portion of the dermis are damaged, leading to the formation of blisters as a way to isolate the affected area from the surrounding skin.

**Why the Correct Answer is Right**
Superficial 2nd degree burns involve damage to the epidermis and a portion of the dermis. This damage causes the skin to become edematous and eventually form blisters, which are filled with serous fluid. The presence of blisters in superficial 2nd degree burns is a characteristic feature that distinguishes them from other types of burns. The blisters act as a barrier to prevent further damage to the deeper layers of the skin.

**Why Each Wrong Option is Incorrect**
**Option A:** 1st degree burns only involve damage to the epidermis, and blisters are not typically seen in this type of burn.
**Option C:** Deep 2nd degree burns involve damage to a larger portion of the dermis, and while blisters may be present, they are often more difficult to identify due to the extent of the burn.
**Option D:** 3rd degree burns involve full-thickness damage to the skin, and blisters are not typically seen in this type of burn.

**Clinical Pearl / High-Yield Fact**
It's essential to assess the depth of a burn by looking for the presence of blisters, as this can help guide treatment and predict the potential for scarring.

**✓ Correct Answer: B. Superficial 2nd degree burn**