What is an essential characteristic of the M240B in a defensive role?

The M240B is known for its capability to deliver high rates of suppression fire, which is crucial in a defensive role. Suppression fire is intended to reduce the enemy's ability to effectively engage friendly forces and to limit their movement. This characteristic makes the M240B particularly valuable in defensive operations, where maintaining the initiative and controlling the battlefield are vital.

In a defensive situation, it is essential to keep the enemy at bay, disrupt their advances, and protect friendly positions. The ability of the M240B to provide rapid and sustained fire helps create that necessary suppression, allowing maneuvering units to reposition, reinforce, or regroup as needed.

While other options might have valid points, they do not encapsulate the primary purpose of the M240B in a defensive context. For example, operating independently isn't always feasible or desired, being lighter than other machine guns doesn't necessarily enhance its defensive capability, and it is typically better suited for suppressive fire over close combat scenarios. Thus, emphasizing the weapon’s suppression capability highlights its essential role in defensive strategies.