The challenges of either party for cause need not all be taken at once, but they may be taken separately, in the following order, including in each challenge all the causes of challenge belonging to the same class and type:
(a) To the panel.
(b) To an individual juror, for a general disqualification.
(c) To an individual juror, for an implied bias.
(d) To an individual juror, for an actual bias.