“Civil infraction determination” means a determination that a person is responsible for a civil infraction by 1 of the following:

  (a) An admission of responsibility for the civil infraction.

  (b) An admission of responsibility for the civil infraction, “with explanation”.

  (c) A preponderance of the evidence at an informal hearing or formal hearing on the question under section 746 or 747.

  (d) A default judgment, for failing to appear as directed by a citation or other notice, at a scheduled appearance under section 745(3) (b) or (4), at a scheduled informal hearing under section 746, or at a scheduled formal hearing under section 747.