Which one of the following statements is true in relation to the offence of abetment?

Unless an offence is successfully committed, there's no question of abetment

For the offence of the abetment to be established, the a better should have been proved to have done something at the time of commission of the offence itself to help its commission

A' returns a licensed weapon belonging to 'B' on his demand with which 'B' commits a murder 'A' is liable for abetment