If any person who may be sworn to give testimony shall willfully fail or refuse to answer any legal and proper question propounded to him concerning the subject of such examination as indicated in § 40.1-6, or if any person to whom a written or printed list of such interrogatories has been furnished by the Commissioner shall neglect or refuse to answer fully and return the same under oath, or if any person in charge of any business establishment shall refuse admission to, or obstruct in any manner the inspection or investigation of such establishment or the proper performance of the authorized duties of the Commissioner or any of his representatives, he shall be guilty of a misdemeanor. Such person, upon conviction thereof, shall be fined not exceeding $100 nor less than $25 or imprisoned in jail not exceeding 90 days, or both.