Read the following statement
i. `B_1` deficiency leads to polyneuritis
ii. `B_2` deficiency leads to chelosis
iii. `B_6` deficiency leads to convulsions

Options

A. Only iand ii are correct
B. Only ii and iii are correct
C. Only iand iii are correct
D. All are correct

Answer

To solve the question regarding the deficiencies of various B vitamins and their associated conditions, we will analyze each statement step by step.

### Step 1: Analyze Statement i
- **Statement**: `B_1` deficiency leads to polyneuritis.
- **Explanation**: Vitamin B1 is known as thiamine. A deficiency in thiamine can lead to neurological disorders, including polyneuritis, which is the inflammation of multiple peripheral nerves. This statement is **correct**.

### Step 2: Analyze Statement ii
- **Statement**: `B_2` deficiency leads to cheilosis.
- **Explanation**: Vitamin B2 is known as riboflavin. A deficiency in riboflavin can cause various symptoms, including cheilosis, which is characterized by cracks and sores at the corners of the mouth. This statement is also **correct**.

### Step 3: Analyze Statement iii
- **Statement**: `B_6` deficiency leads to convulsions.
- **Explanation**: Vitamin B6 is known as pyridoxine. A deficiency in pyridoxine can lead to neurological issues, including seizures or convulsions. Therefore, this statement is **correct** as well.

### Conclusion
After analyzing all three statements, we find that:
- Statement i is correct.
- Statement ii is correct.
- Statement iii is correct.

Thus, all statements are correct.

### Final Answer
The answer is: **All statements are correct.**

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