As a systems administrator, you need to grant a user named 'techuser' the ability to run all commands as any user on a specific Linux server. To accomplish this, you decide to edit the sudoers file. Which of the following entries should you add to the sudoers file using the 'visudo' command to meet this requirement?
techuser ALL=(ALL:ALL) ALL
ALL techuser=(ALL:ALL) ALL
techuser ALL=(ALL) ALL
techuser ANY=(ALL:ALL) NOPASSWD: ALL