Before splitting a 200 meter bracket, what does the observer do during an impact registration?

The correct choice highlights the procedure an observer utilizes during an impact registration, specifically in the context of narrowing down on an accurate target location. Before dividing a 200-meter bracket, the observer first needs to gather sufficient data to ensure that the point of impact is understood. By splitting a 100-meter bracket, the observer can effectively assess whether the rounds are landing within that narrower segment.

This approach allows for a more precise determination of the target's location and aids in adjusting fire more effectively. Conducting this pre-splitting action helps the observer manage and optimize the fire support while ensuring that the units on the ground have the most accurate and effective fire available to them.

In this context, the other options pertain to different methodologies or aspects of fire support that would not accurately describe the necessary preparatory actions preceding the split of a 200-meter bracket. Therefore, focusing on the impact registration with a 100-meter bracket creates a structured pathway to effectively adjust and enhance the accuracy of fire on target.