Read the following statements regarding methanogens and select the correct option.
(i) They are included in the group Archaebacteria.
(ii) They are responsible for the production of biogas in gobar gas plants.
(iii) They live in hot sulphur springs.
(iv) They are strictly anaerobic.

Options

A. Statement(i) and (ii) are correct.
B. Statements (i),(ii) and (iv) are correct
C. Statements (ii),(iii) and (iv) are correct.
D. All statements are correct.

Explanation

To analyze the statements regarding methanogens and determine which are correct, we will evaluate each statement one by one.

### Step-by-Step Solution:

1. **Evaluate Statement (i)**: "They are included in the group Archaebacteria."
- Methanogens are indeed classified as Archaebacteria, which is a group of microorganisms distinct from bacteria and eukaryotes. This statement is **correct**.

2. **Evaluate Statement (ii)**: "They are responsible for the production of biogas in gobar gas plants."
- Methanogens play a crucial role in the production of biogas, particularly in gobar gas plants, where they convert organic matter into methane. This statement is also **correct**.

3. **Evaluate Statement (iii)**: "They live in hot sulphur springs."
- Methanogens do not thrive in hot sulphur springs; they are typically found in anaerobic environments such as marshes or the digestive tracts of ruminant animals. This statement is **incorrect**.

4. **Evaluate Statement (iv)**: "They are strictly anaerobic."
- Methanogens are indeed strictly anaerobic organisms, meaning they cannot survive in the presence of oxygen. This statement is **correct**.

### Conclusion:
Based on the evaluations:
- Statement (i) is correct.
- Statement (ii) is correct.
- Statement (iii) is incorrect.
- Statement (iv) is correct.

Thus, the correct statements are (i), (ii), and (iv). Therefore, the correct option is that statements 1, 2, and 4 are correct.

### Final Answer:
The correct option is: Statements (i), (ii), and (iv) are correct.

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