Vitamin-containing cobalt cyanide linkage is

Options

A. A
B. `B_1`
C. `B_6`
D. `B_12`

Answer

To solve the question "Vitamin-containing cobalt cyanide linkage is," we need to identify which vitamin is associated with a cobalt cyanide linkage.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which vitamin has a cobalt cyanide linkage. This means we need to look for a vitamin that contains cobalt and is linked to a cyanide group.

2. **Analyzing the Options**: The options provided are:
- A) Vitamin A
- B) Vitamin B1
- C) Vitamin B6
- D) Vitamin B12

3. **Identifying the Characteristics of Each Vitamin**:
- **Vitamin A**: This vitamin is primarily involved in vision and immune function but does not contain cobalt or a cyanide linkage.
- **Vitamin B1 (Thiamine)**: This vitamin is important for energy metabolism but does not have a cobalt or cyanide linkage.
- **Vitamin B6 (Pyridoxine)**: This vitamin is involved in amino acid metabolism and neurotransmitter synthesis but does not contain cobalt or cyanide.
- **Vitamin B12 (Cyanocobalamin)**: This vitamin is known for its role in red blood cell formation and neurological function. It contains cobalt and is specifically linked to a cyanide group.

4. **Conclusion**: Based on the analysis, Vitamin B12 is the only vitamin that contains a cobalt cyanide linkage. Therefore, the correct answer is option D) Vitamin B12.

### Final Answer:
The vitamin containing cobalt cyanide linkage is **Vitamin B12**.

---