Employee Leave Request Employee Leave dates requested Role Susan August 15 - August 18 Manager John July 31 - August 16 Manager Ashley August 15 - August 18 Human Resource Specialist Michael August 12 - August 15 Manager Steven August 16 - August 20 Human Resource Specialist Laura August 19 - August 21 Human Resource Specialist Kristen August 18 - August 20 Manager Two managers and one human resource specialist must always be on duty. Based on this information and the above table, for which date are there NOT enough staff members? radio_button_unchecked August 15 radio_button_unchecked August 16 radio_button_unchecked August 17 radio_button_unchecked August 18 radio_button_unchecked August 20