**Core Concept**
The question requires knowledge of the life cycle of the tapeworm *Dichyllobothrium latum*, specifically its intermediate hosts. This parasite is a type of fish tapeworm that infects humans through the consumption of raw or undercooked fish containing its larvae.

**Why the Correct Answer is Right**
The second intermediate host of *D. latum* is a crustacean, specifically the copepod *Cyclops*. The larvae of the parasite infect the copepods in aquatic environments, and humans become infected by consuming contaminated fish. The copepod serves as a crucial link in the life cycle of the parasite, allowing it to complete its development before infecting the definitive host, humans.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not a recognized intermediate host of *D. latum*.
**Option B:** Incorrect because it is not a valid option for the second intermediate host of the parasite.
**Option C:** Incorrect because it is not a known intermediate host of *D. latum*.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the infection with *D. latum* can occur through the consumption of contaminated fish, particularly in regions where the parasite is prevalent. This highlights the importance of proper food handling and cooking practices to prevent parasitic infections.

**Correct Answer:** C. Cyclops.