X Sees Z Committing What Appears to X to Be

Multiple Choice

X sees Z committing what appears to X to be a murder. X in exercise, to the best of his judgement, exerted in good faith, of the powers, which the law gives to all persons of apprehending murderers in the act, seizes Z in order to bring Z before proper authorities. But it turns out that Z was acting in exercise of his right of self defence. X is guilty of

A) No offence
B) Wrongful restraint
C) Wrongful confinement
D) Assault.