C. For any labor organization to exclude from apprenticeship or membership or to deny full and equal membership rights to any applicant for membership because of race or color, sex, sexual orientation, physical or mental disability, religion, age, ancestry or national origin, because of the applicant's previous assertion of a claim or right under former Title 39 or Title 39-A or because of previous actions taken by the applicant that are protected under Title 26, chapter 7, subchapter V-B 5-B; or, because of those reasons, to deny a member full and equal membership rights, expel from membership, penalize or otherwise discriminate with respect to hire, tenure, promotion, transfer, compensation, terms, conditions or privileges of employment, representation, grievances or any other matter directly or indirectly related to membership or employment, whether or not authorized or required by the constitution or bylaws of that labor organization or by a collective labor agreement or other contract; to fail or refuse to classify properly or refer for employment or otherwise discriminate against any member because of race or color, sex, sexual orientation, physical or mental disability, religion, age, ancestry or national origin, because of the member's previous assertion of a claim or right under former Title 39 or Title 39-A or because of previous actions taken by the member that are protected under Title 26, chapter 7, subchapter V-B 5-B; or to cause or attempt to cause an employer to discriminate against an individual in violation of this section, except that it is lawful for labor organizations and employers to adopt a maximum age limitation in apprenticeship programs, if the employer or labor organization obtains prior approval from the Maine Human Rights Commission of any maximum age limitation employed in an apprenticeship program. The commission shall approve the age limitation if a reasonable relationship exists between the maximum age limitation employed and a legitimate expectation of the employer in receiving a reasonable return upon the employer's investment in an