How can you schedule a command to run at a specific time?

The 'at' command is specifically designed for scheduling commands to execute at a specific time in the future. When you use 'at', you can specify an exact time and date when you want the command to be executed. This makes it suitable for one-time tasks that do not need to repeat.

For example, you can enter a command followed by a time specification like 'at 3:00 PM' to run a command exactly at that time. The 'at' daemon makes sure that the scheduled task runs at the designated time, thereby facilitating the scheduling of immediate or future one-off tasks without the need for a separate configuration file.

While the cron command is great for recurring tasks and the batch command is used for executing commands when the system load is lower, they do not cater to the exact scheduling of commands at a specified singular future time as effectively as 'at' does. The mention of a schedule command does not pertain to standard Linux commands, making it an incorrect choice. The use of 'at' is, therefore, the best solution for scheduling a one-time command execution prompt.