The correct entry is 'techuser ALL=(ALL:ALL) ALL' which grants the user 'techuser' the ability to run any command as any user on all hosts. The 'ALL=(ALL:ALL)' portion indicates that from any host (the first 'ALL'), 'techuser' can execute commands as any user (the second 'ALL') and as any group (after the colon). The final 'ALL' specifies that any command can be executed. This entry provides the specific privileges required without providing unnecessary access, adhering to the principle of least privilege. The incorrect answers either do not provide the required privileges, have syntax errors, or grant privileges that are too broad, which could pose a security risk.