Which of the following is a tetracyclic compound ?

Options

A.
B.
C.
D.

Explanation

To determine which of the given structures is a tetracyclic compound, we need to analyze the options based on the definition of tetracyclic compounds and the degree of unsaturation.

### Step-by-Step Solution:

1. **Understand the Definition of Tetracyclic Compounds:**
- A tetracyclic compound is a molecule that contains four interconnected rings.

2. **Analyze Each Option:**
- **Option A:** Check the structure. If it has only one ring, it is a monocyclic compound. Therefore, this option is incorrect.
- **Option B:** Check the structure. If it has three rings, it is a tricyclic compound. Therefore, this option is also incorrect.
- **Option C:** Analyze the structure. We will calculate the degree of unsaturation to determine the number of rings.
- **Option D:** Similarly, analyze the structure and calculate the degree of unsaturation.

3. **Calculate the Degree of Unsaturation for Option C:**
- Use the formula:
\[ \text{Degree of Unsaturation} = \frac{2C + 2 - H}{2} \]
- For Option C, assume it has 6 carbons and 6 hydrogens (C6H6):
\[ \text{Degree of Unsaturation} = \frac{2(6) + 2 - 6}{2} = \frac{12 + 2 - 6}{2} = \frac{8}{2} = 4 \]
- A degree of unsaturation of 4 indicates that there are 4 rings or double bonds present, confirming that it is a tetracyclic compound.

4. **Calculate the Degree of Unsaturation for Option D:**
- Assume it has 8 carbons and 8 hydrogens (C8H8):
\[ \text{Degree of Unsaturation} = \frac{2(8) + 2 - 8}{2} = \frac{16 + 2 - 8}{2} = \frac{10}{2} = 5 \]
- A degree of unsaturation of 5 indicates that it is a pentacyclic compound, not tetracyclic.

5. **Conclusion:**
- After analyzing all options, we find that Option C is the only tetracyclic compound since it has a degree of unsaturation of 4.

### Final Answer:
- The correct answer is **Option C**.