(a) A plea of guilty is an admission of the charge and every material fact alleged therein.
(b) A plea of no contest is a formal declaration that the accused person does not contest the charge. When such a plea is entered, a finding of guilty may be adjudged thereon. The plea cannot be used against the accused person as an admission in any other action based on the same act.
(c) A plea of not guilty denies and puts into issue every material fact alleged in the charge.
(d) If the accused person refuses to plead, the court shall enter a plea of not guilty.