Kevin wanted to make some extra money to help pay for his educational expenses. As he was looking through the classified ads, he saw a job paying $15.00 per hour for part-time bathroom attendant at a local night club. As a part of the bathroom attendant's job duties, that person actually has to stay inside the bathroom at all times and make sure that it is kept in a neat manner. The job asked that only females apply. Kevin applied for the job anyway and accused the club owner of being sexist. Kevin stated that he was going to sue the owner. Based on what you have just read, what additional fact would be needed to make the best argument for the employer as to why his advertisement is not discriminatory.