Which of the following is the MOST secure wireless security protocol?

A junior Linux systems administrator needs to update system software.
Which of the following shell commands would allow the administrator to gain the necessary permissions to update the software?

Corporate management is concerned about the security of the company's mobile phones, in the event they are lost or stolen. Management instructs the IT staff to ensure the data on the devices is not accessible by unauthorized users.
Which of the following would provide the BEST level of protection in this scenario? (Choose two.)

Which of the following physical security measures is intended to mitigate tailgating?

Which of the following provide the BEST security for a server room? (Select two.)