The plaintiffs, deputies of the San Francisco Sheriff's department, appeal the court's decision granting summary judgement to the City of San Francisco. The city implemented a policy prohibiting male deputies from supervising female inmates in the housing unit's jail. The district court concluded that the policy did not violate Title VII's sex discrimination based on the bona fide occupational qualification statute. Based on the scenario, 

(1) What is the two-prong test to justify a BFOQ exception to Title VII's protection against sex discrimination? 

(a) Which prong did the County of San Francisco satisfy? Explain. 

(b) Which prong did the County of San Francisco fail to satisfy?