(a) to any person who is under the age of sixteen years,

(b) to any person whose licence has been suspended, during the period of such suspension, nor to any person whose licence has been revoked,

(c) to any person who has previously been adjudged to be afflicted with or suffering from any mental disability or disease and who has not at the time of application been restored to competency by the methods provided by law,

(d) to any person who is required by this Act to take an examination, unless such person shall have successfully passed such examination,

(e) to any person who is required under the provisions of the motor vehicle financial responsibility laws of this Province to deposit proof of financial responsibility and who has not deposited such proof, or

(f) to any person when the Registrar has reason to believe that the person, because of physical or mental impairment, disease or condition, would not be able to operate a motor vehicle with safety on the highways.