Scenario: A Citrix Engineer created four application layers with different applications at different time stamps as shown below:

App Layer A – Microsoft Office Professional – 15/08/2019, 14:28

App Layer B – Adobe Acrobat Reader and Cisco Webex – 14/07/2019, 11:45

App Layer C – Active Directory Users & Computers, Citrix Studio – 20/08/2019, 16:10 App Layer D – Google Chrome and GoToMeeting – 27/07/2019, 10:35

Which layer would hold the highest priority in this scenario?