Vitamin `B_(12)` consists of which type of element ?

Options

A. Co
B. Nicotin
C. Fe
D. None of these

Answer

### Step-by-Step Solution:

1. **Understanding Vitamin B12**: Vitamin B12 is also known as cobalamin. It is a water-soluble vitamin that plays a crucial role in the functioning of the brain and nervous system, as well as in the formation of blood.

2. **Identifying the Key Element**: The name "cobalamin" indicates that this vitamin contains the element cobalt. Cobalt is essential for the biological activity of vitamin B12.

3. **Evaluating the Options**: The question provides four options to choose from regarding the type of element present in vitamin B12:
- Option A: Cobalt (Co)
- Option B: Nicotinamide
- Option C: Iron (Fe)
- Option D: (not specified in the transcript)

4. **Analyzing Each Option**:
- **Option A (Cobalt)**: This is the correct answer, as vitamin B12 contains cobalt.
- **Option B (Nicotinamide)**: This is incorrect because nicotinamide is associated with vitamin B3, not B12.
- **Option C (Iron)**: This is also incorrect, as iron is not a component of vitamin B12; it is found in other vitamins like vitamin A.
- **Option D**: Not specified, but based on the analysis, it is not necessary for this question.

5. **Conclusion**: The correct answer to the question "Vitamin B12 consists of which type of element?" is **Cobalt (Co)**.

### Final Answer:
Vitamin B12 consists of the element **Cobalt (Co)**.

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