A Linux engineer set up two local DNS servers (10.10.10.10 and 10.10.10.20) and was testing email connectivity to the local mail server using the mail command on a local machine when the following error appeared:

The local machine DNS settings are:

Which of the following commands could the engineer use to query the DNS server to get mail server information?

A Linux administrator needs to analyze a failing application that is running inside a container. Which of the following commands allows the Linux administrator to enter the running container and analyze the logs that are stored inside?

A systems administrator wants to be sure the sudo rules just added to /etc/sudoers are valid. Which of the following commands can be used for this task?

A systems administrator made some changes in the ~/.bashrc file and added an alias command. When the administrator tried to use the alias command, it did not work. Which of the following should be executed FIRST?

A systems administrator has been tasked with disabling the nginx service from the environment to prevent it from being automatically and manually started. Which of the following commands will accomplish this task?