Structures responsible for intracellular transport of materials
(I) E.R. (II) Golgi complex (III) Peroxisomes (IV) Cytoskeleton

Options

A. I and II are correct
B. II and III are correct
C. III and I are correct
D. I and IV are correct

Answer

To determine the structures responsible for intracellular transport of materials, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Analyze the Endoplasmic Reticulum (E.R.)**:
- The endoplasmic reticulum (E.R.) is a network of membranes involved in the synthesis of proteins and lipids. It serves as a channel for transporting these materials within the cell.
- **Conclusion**: The E.R. is responsible for intracellular transport. **(Correct)**

2. **Analyze the Golgi Complex**:
- The Golgi complex is responsible for modifying, sorting, and packaging proteins and lipids that have been synthesized in the E.R. It plays a crucial role in transporting these materials to their final destinations, such as the plasma membrane or lysosomes.
- **Conclusion**: The Golgi complex is also responsible for intracellular transport. **(Correct)**

3. **Analyze Peroxisomes**:
- Peroxisomes are organelles that contain enzymes for breaking down fatty acids and detoxifying harmful substances. They are not primarily involved in the transport of materials within the cell.
- **Conclusion**: Peroxisomes are not responsible for intracellular transport. **(Incorrect)**

4. **Analyze the Cytoskeleton**:
- The cytoskeleton provides structural support and shape to the cell and is involved in cell movement and division. While it plays a role in the transport of materials by facilitating the movement of vesicles, it is not a transport structure itself.
- **Conclusion**: The cytoskeleton is not primarily responsible for intracellular transport. **(Incorrect)**

### Final Answer:
Based on the analysis:
- The structures responsible for intracellular transport of materials are **(I) E.R.** and **(II) Golgi complex**.