The administrator of the division of motor vehicles may deny an application for an instructor’s license or suspend or revoke an instructor’s license after it has been granted for the following reasons:
(1) Any reason set forth in subdivisions (1) — (9) of § 31-10-38.
(2) The applicant’s driving record shows that he or she is not a careful driver.
(3) The applicant has not attained the age of twenty-one (21) years.