Which forward observer control option requires the FO to contact the FIST for each call for fire?

The control option that requires the forward observer (FO) to contact the Fire Support Team (FIST) for each call for fire is the centralized option. In this method, the FO does not have the authority to execute fire missions independently because all fire coordination must go through the FIST. This ensures that all fire support is synchronized and deconflicted, as the FIST acts as the central hub for managing and directing artillery fire.

This approach is particularly useful in complex operational environments where coordination and communication are critical. By requiring the FO to engage the FIST for every fire mission, the risk of friendly fire incidents is minimized and the overall effectiveness of fire support can be enhanced due to consolidated control.