If the observer wishes to control the time of delivery of fire, which method of control would they utilize?

The choice of "At My Command" is the correct answer because this method allows the observer to have absolute control over the timing of when fire is delivered. When using this command, the fire support team or artillery unit will wait for the observer's explicit order to fire. This is particularly important in situations where precise timing is critical, such as when coordinating fire with ongoing maneuvers or ensuring the safety of friendly forces in proximity to the target area.

In contrast, the other methods of control provide varying degrees of autonomy to the firing unit. For example, "Fire When Ready" allows the unit to fire as soon as they are prepared, which could result in earlier rounds hitting the target before the observer has finalized their plan. The "Repeat" command is used to fire the same type of round as the last round fired, but it does not provide specific timing control. "Mark" typically refers to designating a target for observation or adjustment rather than controlling the timing of the fire delivery.

Thus, choosing "At My Command" signifies a direct and deliberate approach, giving the observer full authority over when the rounds will impact the target, aligning with tactics that require precision and coordination.