The matrix of bone is hard due toe ...A ... while that of cartilage is pliable due to ....B …….

Options

A. `{:(A,B),("Calcium salts","Chondroitin salts"):}`
B. `{:(A,B),("Calcium salts","Hyaluronic acid A "):}`
C. `{:(A,B),("Chondroitin Sulphate","Hyaluronic acid "):}`
D. `{:(A,B),("Chondroitin Sulphate","Calcium salts"):}`

Answer

To solve the question regarding the matrix of bone and cartilage, we need to identify the components that contribute to their respective properties.

### Step-by-Step Solution:

1. **Understanding Bone Composition**:
- Bone is a type of connective tissue that is known for its hardness. The primary reason for this hardness is the presence of certain minerals in its matrix.
- **A**: The matrix of bone is hard due to the presence of **calcium salts**. Calcium phosphate is a major component that contributes to the rigidity and strength of bone.

2. **Understanding Cartilage Composition**:
- Cartilage is another type of connective tissue, but it is known for being more flexible and pliable compared to bone. The matrix of cartilage contains different components that allow it to maintain its shape while being flexible.
- **B**: The matrix of cartilage is pliable due to the presence of **chondroitin sulfate**. This is a type of glycosaminoglycan that provides elasticity and support to the cartilage.

3. **Final Answer**:
- Therefore, the complete answer to the question is:
- A: Calcium salts
- B: Chondroitin sulfate

### Final Answer:
The matrix of bone is hard due to **calcium salts** (A), while that of cartilage is pliable due to **chondroitin sulfate** (B).

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