The study of worms is called

Options

A. Nematology
B. Cnidology
C. Helminthology
D. Arthrology

Answer

To determine the correct answer to the question "The study of worms is called," we can analyze the options provided:

1. **Pneumatology**: This term refers to the study of Pneumatodes, which are roundworms. The root "pneumato" relates to air or gas, not specifically to worms in general.

2. **Nidology**: This term refers to the study of nests, particularly in birds, and is not related to worms at all.

3. **Helminthology**: This term is derived from "helminth," which means worms, and "logy," which means study. Therefore, Helminthology is specifically the study of worms, including parasitic worms.

4. **Arthrology**: This term refers to the study of arthropods, which are a different group of animals that include insects, arachnids, and crustaceans, and is not related to worms.

Based on this analysis, the correct answer is **Helminthology**, as it specifically pertains to the study of worms.

### Step-by-Step Solution:
1. Identify the terms related to the study of worms.
2. Analyze each term:
- **Pneumatology**: Study of Pneumatodes (roundworms).
- **Nidology**: Study of nests (not related to worms).
- **Helminthology**: Study of worms (correct answer).
- **Arthrology**: Study of arthropods (not related to worms).
3. Conclude that the correct term for the study of worms is **Helminthology**.