(a)    Notwithstanding any other provision of this subtitle, this subtitle does not prohibit:

(1)    an employer from hiring and employing employees, an employment agency from classifying or referring for employment any individual, a labor organization from classifying its membership or classifying or referring for employment any individual, or an employer, labor organization, or joint labor–management committee controlling apprenticeship or other training or retraining programs from admitting or employing any individual in a program, on the basis of the individual’s sex, age, religion, national origin, or disability, if sex, age, religion, national origin, or disability is a bona fide occupational qualification reasonably necessary to the normal operation of that business or enterprise;

(2)    an employer from establishing and requiring an employee to adhere to reasonable workplace appearance, grooming, and dress standards that are directly related to the nature of the employment of the employee and that are not precluded by any provision of State or federal law, as long as the employer allows any employee to appear, groom, and dress consistent with the employee’s gender identity;

(3)    a school, college, university, or other educational institution from hiring and employing employees of a particular religion, if:

(i)    the institution is wholly or substantially owned, supported, controlled, or managed by a particular religion or by a particular religious corporation, association, or society; or

(ii)    the curriculum of the institution is directed toward the propagation of a particular religion; or

(4)    except as provided in subsection (b) of this section, an employer, employment agency, or labor organization from observing the terms of a bona fide seniority system or any bona fide employee benefit plan, such as a retirement, pension, or insurance plan, that is not a subterfuge to evade the purposes of this subtitle.

(b)    An employee benefit plan may not excuse the failure to hire any individual.