Which of the following is the most important monomer component of the chitinous exoskeleton of arthropods ?

Options

A. N-acetyl glucosamine
B. Taurocholic acid
C. Hyaluronic acid
D. D - glucosamine

Answer

To solve the question regarding the most important monomer component of the chitinous exoskeleton of arthropods, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Composition of Chitin**:
- Chitin is a polysaccharide that forms the exoskeleton of arthropods. It is important to identify its monomer components.

2. **Identify the Monomer of Chitin**:
- The primary monomer of chitin is N-acetylglucosamine (GlcNAc), which is a derivative of glucose.

3. **Evaluate the Options**:
- **Option A**: N-acetylglucosamine - This is the correct answer as it is the monomer that polymerizes to form chitin.
- **Option B**: Taurocholic acid - This is a bile acid and not related to chitin.
- **Option C**: Hyaluronic acid - This is found in connective tissues and not in chitin.
- **Option D**: D-glucosamine - While related, it is not the primary monomer of chitin; it is an isomer of N-acetylglucosamine.

4. **Conclusion**:
- Based on the evaluation, the most important monomer component of the chitinous exoskeleton of arthropods is **N-acetylglucosamine**.

### Final Answer:
**N-acetylglucosamine**