Explanation:

- In cases where an offence is punishable with a fine only, the inability to pay that fine can lead to imprisonment.

- The imprisonment is essentially enforced as a way to compel the payment of the fine.

- The duration of such imprisonment varies depending on the jurisdiction and statutory provisions.

1. Four months: This is a possibility but may not be applicable in this context.

2. Six months: This is often the maximum term for imprisonment when a fine is unpaid in cases of fines around Rs. 1,000/-.

3. One year: Generally applicable for higher fines or different situations.

4. Two years: Typically not applicable for minor fines.