What method utilizes a device to quickly assess distance during immediate range determination?

The correct choice, which is the Laser Range Finder (LRF), is a device specifically designed to measure distances quickly and accurately. It works by emitting a laser beam towards a target and calculating the time it takes for the beam to return after reflecting off the target. This method provides a precise measurement of distance, which is crucial for effective targeting and engagement in direct fire situations. The quick assessment capability of the LRF allows for dynamic adjustments during combat scenarios where timing and accuracy are of utmost importance.

Other methods such as map reference rely on pre-existing geographical data and calculations, which can be time-consuming and less accurate. The MIL (minute of angle) relationship involves calculations based on the size of targets and distance, which also requires time and practice to apply effectively. Lastly, using an adjacent element for distance determination depends on the visibility and reliability of the nearby units' assessments, which might not always be feasible or accurate in certain combat situations. The LRF stands out for its speed and precision, making it the most effective method in the context of immediate range determination.