**Core Concept**
Herpes simplex virus (HSV) is a type of DNA virus that causes a range of clinical manifestations, from mild skin lesions to severe encephalitis. The virus infects neurons and remains latent in the ganglia, periodically reactivating to cause recurrent episodes of infection.

**Why the Correct Answer is Right**
HSV primarily infects the trigeminal nerve, resulting in oral or genital lesions, depending on the type of virus. Type 1 HSV (HSV-1) typically causes oral herpes, while Type 2 HSV (HSV-2) is more commonly associated with genital herpes. The virus enters the host through mucosal surfaces or skin abrasions, and once inside, it replicates within the epithelial cells before infecting neurons.

**Why Each Wrong Option is Incorrect**
**Option A:** This choice is incorrect as it does not specify the correct location of HSV infection. While HSV can infect other areas of the body, the primary sites of infection are the oral or genital regions.
**Option B:** This option is incorrect as it does not correctly identify the type of virus associated with the condition. HSV-1 and HSV-2 are the two main types of HSV, and the correct answer should specify the correct type of virus.
**Option C:** This choice is incorrect as it does not accurately describe the mode of transmission of HSV. The virus is primarily spread through skin-to-skin contact or through mucosal surfaces, not through airborne transmission.

**Clinical Pearl / High-Yield Fact**
HSV is a common cause of encephalitis, particularly in immunocompromised patients, and prompt diagnosis and treatment are essential to prevent severe neurological sequelae.

**Correct Answer: D. Genital herpes is caused by Type 2 Herpes Simplex Virus (HSV-2).**