Explanation:

- Option 1: Always an offence

This means abetment is a crime no matter what. But in law, not all abetment is punishable—only if the law specifically says so.

- Option 2: Never an offence

This is incorrect. Abetment can be an offence, depending on the situation.

- Option 3: May be an offence depending on the circumstances but not always

This is correct. Abetment is punishable only in circumstances defined by law (e.g., where the act abetted is actually committed, or the law specifically punishes attempt or abetment).

- Option 4: None

This means none of the above are true, which is not accurate here.