Which form should an observer use to record the rounds and spottings in relation to the registration point?

The correct choice is the DA 5429, which is specifically designed for recording fire mission results and observing rounds in relation to a registration point. This form allows the observer to systematically document the impact of rounds relative to the designated registration point, providing essential information for future fire missions.

Using the DA 5429 helps maintain clear communication and accountability by having a structured way to analyze and report fire support results. The data captured on this form aids in evaluating the effectiveness of the fire support and can also be used for adjustment in subsequent missions to ensure precision and accuracy in supporting the maneuver element.

The other options do not serve this specific purpose related to fire support documentation. For instance, the DA 4187 is typically used for personnel actions, while the DA 2185 relates to personnel training and evaluations, and the Shell Report may provide information on munitions but lacks the systematic approach provided by the DA 5429 for observers in the context of fire support operations.