**Core Concept**
The guinea worm, also known as *Dracunculus medinensis*, is a parasitic worm that causes dracunculiasis. The life cycle of the guinea worm involves two hosts: a definitive human host and an intermediate host.

**Why the Correct Answer is Right**
The correct answer is related to the life cycle of the guinea worm, which involves water fleas or copepods as intermediate hosts. When an infected person releases guinea worm larvae into water, the larvae are ingested by copepods, where they develop into infective third-stage larvae.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not a known intermediate host for the guinea worm.
**Option B:** Incorrect as it does not participate in the life cycle of *Dracunculus medinensis*.
**Option D:** Incorrect because it is not involved in the transmission of the guinea worm.

**Clinical Pearl / High-Yield Fact**
A key fact to remember is that the guinea worm's life cycle can be broken by preventing the ingestion of contaminated water, highlighting the importance of water treatment and hygiene in disease prevention.

**Correct Answer:** C. Copepods.