Which of the following is one of the authorized commands of execution?

The command "Fire" is one of the key authorized commands of execution in military operations, particularly when it comes to firearms and weapon systems. This command is critical as it communicates the instruction to initiate the discharge of a weapon. When "Fire" is issued, it signals to personnel to engage the target immediately, reflecting the culmination of the preparation and aiming process. The clarity and decisiveness of this command ensure that troops act cohesively and understand that they are clear to take action.

In contrast, while the other options may represent actions in tactical scenarios, they do not serve as commands of execution that directly instruct personnel to discharge their weapons. For instance, "Adjust" might refer to alterations in aim or position based on guidance or an assessment of conditions, while "Engage" typically denotes the initiation of engagement without the explicit command to fire. Meanwhile, "Cease" instructs personnel to stop firing, which is critical but does not relate to the execution of a command to fire in the same direct manner. Thus, "Fire" stands out as the clear and authoritative command necessary for action in a shooting context.