Pellagra is caused by the deficiency of:

Options

A. Pyridoxine
B. Folic acid
C. Biotin
D. Niacin

Answer

### Step-by-Step Solution:

1. **Understanding Pellagra**: Pellagra is a disease that arises due to a deficiency of certain nutrients in the diet. It is important to identify which nutrient is lacking to understand the cause of this disease.

2. **Identifying the Nutrient**: The key nutrient associated with Pellagra is Niacin, also known as Vitamin B3. When the intake of Niacin is insufficient, it leads to the development of Pellagra.

3. **Symptoms of Pellagra**: The symptoms of Pellagra include:
- Diarrhea
- Dermatitis (skin sores)
- Dementia (mental confusion)
These symptoms arise due to the lack of Niacin in the body.

4. **Examining Other Options**: The question may provide multiple-choice options. It is essential to differentiate Niacin from other vitamins:
- Pyridoxine (Vitamin B6) deficiency leads to different symptoms.
- Folic Acid (Vitamin B9) deficiency causes other health issues.
- Biotin (Vitamin B7) deficiency is also unrelated to Pellagra.

5. **Conclusion**: Based on the information gathered, Pellagra is specifically caused by a deficiency of Niacin (Vitamin B3).

### Final Answer:
Pellagra is caused by the deficiency of Niacin (Vitamin B3).

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