Correct Answer:
B. Guilty of abetting B to commit murder
In the scenario where A instigates B to murder C, A is guilty of abetting B to commit murder, even if B refuses to carry out the act. The foundational concept here is that the offence of abetment is complete the moment the instigation occurs. It is not contingent upon the principal offence actually being committed. A's criminal intent and the act of instigation are sufficient to establish guilt for abetment. Therefore, option B is correct. Option A is false because B's refusal does not negate A's criminal act of instigation.