Choose the most appropriate statement regarding hand washing. a) using an alcohol-based hand gel or foam is an effective way to disinfect your hands when there is no visible contaminant b) washing your hands with soap and water is the only proper way to disinfect your hands after contact with someone's bare skin c) when you have visible contaminant on your hands, using an alcohol gel or foam is effective to disinfect as long as you wipe the contaminant off of your hands with a disposable towel first d) you need to wash your hands with soap and warm running water for a minimum of 2 minutes to properly disinfect them