Which of the following is a type of preparatory command?

A preparatory command serves to alert individuals that a command is about to follow, allowing them to get ready for the upcoming action. In military drills and formations, these commands prepare the personnel for execution. In this context, "Right" is a type of preparatory command as it indicates the direction in which individuals need to orient themselves or prepare to move.

While the other choices point to specific movements or actions, they do not serve the same preparatory function as 'Right' does, as they lack the context of indicating an action that is about to be executed. Thus, identifying "Right" as a preparatory command hinges on its role in giving a signal for readiness before an actual command is issued to perform a specific movement.