To determine the nature of abetment of an offence:
1. Under Section 107 of the Indian Penal Code, 1860, abetment of an offence—whether by instigating, aiding, or conspiring—is itself an offence, punishable under Sections 108 and 109.
2. The liability exists regardless of whether the principal offence is committed, making it always an offence if the abetment conditions are met.
3. It does not depend on circumstances or police discretion alone.
Therefore, the correct answer is (1) Always an offence.