4.3.A person who is eligible to sit for the prequalification examination referred to in section 4.2 must register for that purpose with the Commission, pay the fees fixed by the Regulation respecting the issuance of competency certificates (chapter R-20, r. 5) and undergo that examination not later than the last day of the fourth full month following the issuance of the apprentice competency certificate corresponding to the trade of crane operator.