Changes in Britain' s National Health Service have led many British hospitals to end on-site laundry services for their staff. Although the water in a typical residential washing machine, unlike that in the industrial washing machines used by hospitals, does not reach temperatures high enough to kill the dangerous bacterium Acinetobacter, hospital officials believe that the discontinuation of these services will not put patients at risk. Which one of the following, if true, most helps to justify the hospital officials' belief? ['Hospital patients infected with Acinetobacter can be isolated from other patients.', 'Water in residential washing machines reaches temperatures high enough to kill all dangerous bacteria other than Acinetobacter.', 'Most hospital staff made use of the on-site laundry services before they were discontinued.', 'Hospital staff are instructed to use clothes dryers at temperatures high enough to kill Acinetobacter.']