No person carrying on or conducting within this state any business requiring employees may refuse to hire, employ, or license, or may bar or discharge from employment, any individual solely upon the ground of age; when the reasonable demands of the position do not require an age distinction; and, provided that such individual is well versed in the line of business carried on by such person, and is qualified physically, mentally, and by training and experience to satisfactorily perform the duties assigned to the person or for which the person applies. Nothing herein affects the retirement policy or system of any employer if such policy or system is not merely a subterfuge to evade the purposes of this section. Any person who violates any of the provisions of this section is guilty of a class B misdemeanor.