White fibres and reticular fibres are composed of  

Options

A. elastin
B. keratin
C. fibrin
D. collagen, reticulin

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the composition of white fibers and reticular fibers. These fibers are types of connective tissue fibers.

2. **Identifying White Fibers**: White fibers, also known as collagen fibers, are primarily composed of collagen. Collagen is a structural protein that provides strength and support to various tissues in the body.

3. **Identifying Reticular Fibers**: Reticular fibers are made up of a protein called reticulin. These fibers are thinner and form a network that supports the cells in certain tissues, particularly in lymphoid organs.

4. **Analyzing the Options**: The options provided are elastin, keratin, fibrin, collagen, and reticulin.
- **Elastin**: This protein is found in elastic fibers, not in white or reticular fibers.
- **Keratin**: This is a structural protein found in hair and nails, not in connective tissue fibers.
- **Fibrin**: This protein is involved in blood clotting, not in the structure of connective tissue fibers.
- **Collagen**: This is the correct component of white fibers.
- **Reticulin**: This is the correct component of reticular fibers.

5. **Conclusion**: The correct answer to the question is that white fibers are composed of collagen and reticular fibers are composed of reticulin.

### Final Answer:
White fibers are composed of **collagen**, and reticular fibers are composed of **reticulin**.

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