Haversian canals are found in

Options

A. Matrix of mamalian bone
B. Matrix of amphibian bone
C. Matrix of reptilian bone
D. All of these

Explanation

**Step-by-Step Solution:**

1. **Understanding Haversian Canals**: Haversian canals are specialized structures found within bone tissue. They are central canals that run through the bone and are part of the Haversian system (or osteon), which is crucial for bone health and function.

2. **Identifying the Location**: Haversian canals are primarily found in mammalian bones. They contain blood vessels (arteries and veins), nerves, and lymphatic vessels, which are essential for supplying nutrients and removing waste from bone cells.

3. **Analyzing the Options**:
- **Option 1**: Matrix of mammalian bone - This is correct because Haversian canals are indeed found within the matrix of mammalian bone.
- **Option 2**: Matrix of amphibian bone - This is incorrect as Haversian canals are not a feature of amphibian bones.
- **Option 3**: Matrix of reptilian bone - This is also incorrect since Haversian canals are not characteristic of reptilian bones.
- **Option 4**: All of these - This option is incorrect because only the first option is true.

4. **Conclusion**: Based on the analysis, the correct answer is that Haversian canals are found in the matrix of mammalian bone.

**Final Answer**: Haversian canals are found in the matrix of mammalian bone.

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