In very narrowly defined situations, an employer is permitted to discriminate on the basis of a protected trait if the trait is a bona fide occupational qualification (BFOQ) reasonably necessary to the normal operation of that particular business or enterprise. To make a BFOQ defense, an employer must prove three elements: a direct relationship between the trait and the ability to perform the job; the BFOQ's relation to the "essence" or "central mission of the employer's business", and that there is no less restrictive or reasonable alternative ("United Automobile Workers v. Johnson Controls, Inc.", 111 S.Ct. 1196). BFOQ is an extremely narrow exception to the general prohibition of discrimination based on protected traits ("Dothard v. Rawlinson", 97 S.Ct. 2720). An employer or customer's preference for an individual of a particular religion is not sufficient to establish a BFOQ ("Equal Employment Opportunity Commission v. Kamehameha School—Bishop Estate", 990 F.2d 458 (9th Cir. 1993)).