## Core Concept
The question tests knowledge of treatments for scabies, a skin infestation caused by the mite *Sarcoptes scabiei*. The focus is on oral medications used in a single dose for scabies treatment.

## Why the Correct Answer is Right
Ivermectin is an antiparasitic drug that works by interfering with the nervous system of the mite, leading to its death. It is effective against scabies when given orally in a single dose or two doses separated by a week. Ivermectin is particularly useful for mass treatment and for patients who cannot tolerate topical treatments.

## Why Each Wrong Option is Incorrect
* **Option A:** This option is blank and does not provide a valid choice.
* **Option B:** This option is also blank and does not offer a viable alternative.
* **Option C:** This option is blank as well, failing to present a credible option for scabies treatment.
* **Option D:** This option is blank, similar to the other incorrect choices.

## Clinical Pearl / High-Yield Fact
A key point to remember is that ivermectin, when used for scabies, can be given as a single dose of 200 mcg/kg or as two doses of 100 mcg/kg given one week apart. This regimen has been shown to be effective in treating scabies.

## Correct Answer: C. Ivermectin.