A free living roundworm is

Options

A. Enterobius
B. Rhabditis
C. Dracunculus
D. All the above

Answer

To answer the question "A free-living roundworm is," we need to analyze the options provided: Enterobius, Rhabditis, Dracunculus, and all of the above.

### Step-by-Step Solution:

1. **Understand the Characteristics of Roundworms**:
- Roundworms belong to the phylum Nematoda. They can be free-living or parasitic. Free-living roundworms typically inhabit soil or aquatic environments.

2. **Evaluate the Options**:
- **Enterobius**: This is known as Enterobius vermicularis, commonly referred to as the pinworm. It is a parasitic roundworm that infects the intestines of humans, making it an incorrect choice for a free-living roundworm.

- **Rhabditis**: This is a genus of free-living nematodes. Rhabditis species are typically found in soil and decaying organic matter, making this option a correct answer for a free-living roundworm.

- **Dracunculus**: This refers to Dracunculus medinensis, known as the guinea worm. It is a parasitic worm that infects humans and is not free-living, thus making this option incorrect.

- **All of the above**: Since Enterobius and Dracunculus are both parasitic, this option is also incorrect.

3. **Conclusion**:
- The only correct answer among the options provided is **Rhabditis**, as it is a free-living roundworm.

### Final Answer:
A free-living roundworm is **Rhabditis**.