In an accident, when is it compulsory to help?

A)Only when I am involved in the accident.
B)When I see that the injured have not yet been attended to.Correct
C)It is not compulsory in any case.
Any person who witnesses, encounters or is involved in an accident is obliged to provide assistance, when necessary and provided that there is no risk to themselves or to others.
Failure to do so constitutes the offence of failure to render assistance under the criminal code. The same applies to those who, being unable to provide assistance, do not urgently call for the help of others.

Road users who notice an accident but are not involved in it are not obliged to stop when their cooperation is clearly not necessary or when the authorities or their agents have already arrived at the scene of the accident.