Hookworm has

Options

A. Necator americanus
B. Ancylostoma duodenale
C. Ancylostoma caninum
D. Strongyloides stercoralis

Answer

To answer the question "Hookworm has," we need to identify which of the given options are classified as hookworms.

### Step-by-Step Solution:

1. **Understanding Hookworms**:
- Hookworms are parasitic nematodes that belong to the phylum Aschelminthes (also known as Nemathelminthes). They primarily infect the intestines and can cause various health issues like anemia, diarrhea, and malnutrition.

2. **Analyzing the Options**:
- **Option 1: Necator americanus**: This is known as the New World hookworm. It is indeed a type of hookworm.
- **Option 2: Cyclostoma duodenum**: This is referred to as the Old World hookworm and is also a type of hookworm.
- **Option 3: Cyclostoma caninum**: This species infects canines (dogs) and is classified as a hookworm.
- **Option 4: Strongyloides stercoralis**: This is commonly known as threadworm and is not classified as a hookworm.

3. **Conclusion**:
- The correct answer to the question is that hookworms include Necator americanus, Cyclostoma duodenum, and Cyclostoma caninum. Strongyloides stercoralis is not a hookworm.

### Final Answer:
- Hookworm has: **Necator americanus, Cyclostoma duodenum, and Cyclostoma caninum**.