What is the phase line used to control the forward progress of an attack?

The limit of advance serves as a crucial phase line in military operations, particularly in an attack. It designates the maximum distance that attacking forces are permitted to advance without further coordination or approval. This line plays a vital role in maintaining control over the maneuvering forces, ensuring they don't exceed established boundaries without the necessary oversight.

By employing a limit of advance, commanders can effectively manage operational tempo, assess the situation on the ground, and coordinate reinforcements or adjustments as necessary. This also helps prevent overextension, which can leave units vulnerable and disrupt the overall battle plan.

In the context of the options given, the limit of advance distinctly specifies the forward control of an attack unlike other concepts such as a coordination point, which is more about establishing communication and guidance, or an attack position, which focuses on a designated start point for the attack. The disengagement line pertains to a point where forces may pull back, not where they proceed forward in an offensive operation. Thus, the limit of advance is specifically tailored to regulate the aggressive movements of forces during an attack.