**Core Concept**
Herpes gestationalis, also known as pemphigoid gestationis, is an autoimmune blistering disease that occurs during pregnancy. It is characterized by the formation of tense blisters on the abdomen, often accompanied by pruritus. The condition is thought to be triggered by the immune system's response to fetal antigens.

**Why the Correct Answer is Right**
Herpes gestationalis is caused by the production of autoantibodies against the basement membrane zone of the skin, specifically targeting the collagen XVII protein. This leads to the activation of complement and the deposition of immune complexes, resulting in blister formation. The condition is often associated with a strong maternal immune response to the fetus, which can lead to the production of anti-fetal antibodies.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the pathophysiology of herpes gestationalis. While herpes simplex virus can cause skin lesions, it is not associated with this specific condition.

**Option B:** This option is incorrect because it does not accurately describe the clinical presentation of herpes gestationalis. While pemphigus vulgaris is an autoimmune blistering disease, it is characterized by the formation of flaccid blisters, not tense blisters.

**Option C:** This option is incorrect because it does not accurately describe the triggers of herpes gestationalis. While stress and hormonal changes can exacerbate the condition, they are not thought to be primary triggers.

**Option D:** This option is incorrect because it does not accurately describe the immune response in herpes gestationalis. While the condition is associated with a strong maternal immune response, it is not characterized by the production of autoantibodies against the skin.

**Clinical Pearl / High-Yield Fact**
Herpes gestationalis is often associated with a strong maternal immune response to the fetus, which can lead to the production of anti-fetal antibodies. This can increase the risk of preterm labor and fetal loss.

**Correct Answer:** D.