Which fuze setting must be adjusted for pre-established detonation times in certain bombs?

The time-to-burst setting is the correct choice because it directly impacts the detonation timing of the bomb. This setting allows munitions personnel to configure the fuze to detonate the bomb at a specific time after release, which is critical for achieving the desired effects in target engagements. Adjusting this setting ensures that the bomb detonates at the pre-established time, maximizing its effectiveness based on tactical considerations and target dynamics.

The firing delay and impact sensitivity, while important attributes of a fuze, do not specifically pertain to adjusting pre-established detonation times. Firing delay relates to the time interval before detonation occurs after a triggering event, whereas impact sensitivity is a measure of how easily a fuze will detonate upon impact. Safety arming is focused on preventing accidental detonation before the bomb is intended to be used, rather than adjusting detonation times. Thus, the time-to-burst setting is essential for controlling when the bomb detonates relative to its release, confirming it as the appropriate fuze setting for pre-established detonation times.