From retinulae, the sensory fibres leave as optic nerves and reach 

Options

A. tritocerebrum
B. deutocerebrum
C. protocerebrum
D. segmental ganglion

Answer

To answer the question "From retinulae, the sensory fibres leave as optic nerves and reach," we need to analyze the options provided and understand the role of retinulae in the nervous system.

### Step-by-Step Solution:

1. **Understand Retinulae**: Retinulae are the light-sensitive structures found in the compound eyes of arthropods. They contain photoreceptor cells that convert light into neural signals.

2. **Identify the Pathway of Sensory Fibres**: The sensory fibres that originate from the retinulae leave as optic nerves. These optic nerves carry visual information to specific parts of the nervous system.

3. **Evaluate the Options**: The options given are:
- Tritocerebrum
- Deutocerebrum
- Protocerebrum
- Segmental ganglia

4. **Analyze Each Option**:
- **Segmental Ganglia**: This is part of the peripheral nervous system and is not where the optic nerves terminate.
- **Tritocerebrum**: This is involved in integrating sensory information but is not the primary destination for optic nerves.
- **Deutocerebrum**: This part is primarily associated with the antennae and olfactory information, not visual information.
- **Protocerebrum**: This is the part of the brain that processes visual information from the optic nerves.

5. **Conclusion**: The sensory fibres from the retinulae leave as optic nerves and reach the **protocerebrum**, which is responsible for processing visual signals.

### Final Answer:
From retinulae, the sensory fibres leave as optic nerves and reach the **protocerebrum**.