## Core Concept
Lice are ectoparasites that feed on human blood and can act as vectors for various diseases. The primary species of lice that infest humans are *Pediculus humanus capitis* (head lice), *Pediculus humanus corporis* (body lice), and *Phthirus pubis* (pubic lice). They are known to transmit certain diseases through their feces or saliva.

## Why the Correct Answer is Right
The correct answer, , involves understanding which diseases are transmitted by lice. Lice are known vectors for:
- **Epidemic typhus (Rickettsia prowazekii)**: transmitted through the feces of infected body lice.
- **Trench fever (Bartonella quintana)**: transmitted through the feces of infected body lice.
- **Relapsing fever (Borrelia recurrentis)**: transmitted through the feces of infected body lice.

## Why Each Wrong Option is Incorrect
- **Option A:** Epidemic typhus is indeed transmitted by lice, specifically body lice. Therefore, this option is incorrect because lice are vectors for this disease.
- **Option B:** Trench fever is also transmitted by body lice, making this option incorrect as well.
- **Option D:** Relapsing fever, caused by *Borrelia recurrentis*, is transmitted by the body louse, not the tick. This makes option D incorrect.

## Clinical Pearl / High-Yield Fact
A key point to remember is that while lice can transmit several diseases, their role in spreading *Rickettsia typhi* (murine typhus) is not established; murine typhus is primarily transmitted by fleas. This distinction can be critical in clinical practice and epidemiology.

## Correct Answer Line
**Correct Answer: D. Murine typhus**.