**Core Concept**
Scabies is a skin infestation caused by the mite Sarcoptes scabiei, leading to intense itching and skin lesions. The treatment of choice aims to eliminate the mite and its eggs, providing relief from symptoms and preventing transmission.

**Why the Correct Answer is Right**
Permethrin cream 5% is the treatment of choice for scabies due to its high efficacy and safety profile. It works by disrupting the mite's nervous system, ultimately leading to its death. Permethrin is also lipophilic, allowing it to penetrate into hair follicles where the mite resides. A single application is usually sufficient, and it is recommended to treat all close contacts simultaneously to prevent re-infestation.

**Why Each Wrong Option is Incorrect**
**Option A:** Ivermectin is an alternative treatment for scabies, but it is not the first-line choice. It is often used in patients with resistance to permethrin or in cases of severe infestation.
**Option B:** Lindane is an older treatment for scabies, but it has fallen out of favor due to concerns about its toxicity and potential for neurotoxicity.
**Option C:** Sulfur ointment is an older treatment for scabies, but it is less effective and more irritating to the skin compared to permethrin.

**Clinical Pearl / High-Yield Fact**
It's essential to treat all close contacts of a scabies patient simultaneously, even if they are asymptomatic, to prevent re-infestation. This includes family members, sexual partners, and caregivers.

**Correct Answer: C. Sulfur ointment is an older treatment for scabies, but it is less effective and more irritating to the skin compared to permethrin.**