(a) After hearing and considering the evidence or argument, the registrar shall promptly determine the challenge and issue a decision in writing.
(b) If the registrar determines that the voter's registration should not be canceled, the registration continues in effect.
(c) If the registrar determines that the voter's registration should be canceled, the registrar shall cancel the registration on the 31st day after the date the registrar's decision is issued.
(d) The registrar shall retain a copy of the decision on file with the duplicate registration certificate of the voter whose registration was challenged and shall deliver a copy to each party to the challenge.