Which of the following vitamin is Naphtha-quinone derivative ?

Options

A. A
B. B
C. D
D. K

Answer

To determine which vitamin is a naphthaquinone derivative, we will analyze the given options: Vitamin A, B, D, and K.

### Step 1: Identify the Chemical Names of Each Vitamin
- **Vitamin A**: Known as **Retinol**.
- **Vitamin B**: Refers to a complex of vitamins (B1, B2, B12, etc.) collectively known as **Vitamin B Complex**.
- **Vitamin D**: Known as **Calciferol**.
- **Vitamin K**: Known as **Phylloquinone** (also includes forms like MK4 and MK7).

### Step 2: Analyze the Structure of Each Vitamin
- **Vitamin A (Retinol)**: Contains a beta-ionone ring and does not have a naphthaquinone structure.
- **Vitamin B Complex**: These vitamins have various structures, none of which resemble naphthaquinone.
- **Vitamin D (Calciferol)**: Contains a steroid structure and does not resemble naphthaquinone.
- **Vitamin K (Phylloquinone)**: Contains a naphthaquinone structure, characterized by a benzene ring with two ketone groups.

### Step 3: Conclusion
From the analysis, we find that:
- Vitamin K (Phylloquinone) is the only vitamin that has a structure resembling naphthaquinone.

Thus, the answer is **Vitamin K**.

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