Police chief: This department' s officers are, of course, prohibited from drinking on the job. However, there is one exception: it is extremely valuable for officers to work undercover to investigate nightclubs that have chronic crime problems, and officers may drink in moderation during such work. Which one of the following, if true, most helps to justify the exception to the police department's rule stated above? ['Only very experienced police officers are allowed to work undercover investigating nightclubs.', 'Over the last several years, the police department has significantly increased its undercover operations in nightclubs.', 'Many nightclub patrons would suspect that people in a nightclub who refrained from drinking were police officers.', 'For the most part, the public is aware that police officers are allowed to drink during undercover operations in nightclubs.']