Locomotion is directly helped by:-

Options

A. Setae
B. Mucous secreted by body segments
C. Rhythmic contraction of body segments
D. Pharynx

Answer

**Step-by-Step Solution:**

1. **Understanding Locomotion in Cockroaches**: Locomotion in cockroaches involves the movement of their body segments and the coordination of their muscles.

2. **Identifying Key Processes**: The question asks which process directly helps in locomotion. The options provided include:
- Setae
- Mucus which creates body segments
- Rhythmic contraction of body segments
- Farings

3. **Analyzing Each Option**:
- **Setae**: These are stiff hairs found in some organisms, like earthworms, that help grip the substrate. However, cockroaches do not have setae for locomotion.
- **Mucus**: While mucus can play a role in movement for some organisms, it is not a primary factor in cockroach locomotion.
- **Rhythmic contraction of body segments**: This refers to the coordinated contraction and relaxation of muscles in the body segments, which is crucial for movement in cockroaches.
- **Farings**: This term is not commonly associated with locomotion in cockroaches and does not apply here.

4. **Conclusion**: The most relevant and direct process that aids in the locomotion of cockroaches is the rhythmic contraction of body segments. This allows for effective movement as the muscles contract and relax in a coordinated manner.

5. **Final Answer**: Therefore, the correct answer is option 3: Rhythmic contraction of body segments.

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