Viral infection causing blisters on skin of lips, nose, or genitals: (A) Pneumocystis carinii pneumonia (B) Toxoplasmosis (C) Cryptococcus (D) Herpes simplex (E) Kaposi sarcoma

Letter D, Herpes simplex

Explanation:

Herpes simplex is caused by the herpes virus (HSV). The herpes virus can infect different parts of the body depending on the type of virus.

HSV-1: cusses blisters around the mouth, including eyes in the case of several infections.

HSV-2: responsible for genital infections.

The signs and symptoms include blistering in the infecting area, itching and flu-like symptoms (fever, headache, etc.)