Ammunition for the M240B is fed from which of the following?

The M240B machine gun utilizes a 200-round belt of ammunition for feeding. This belt is typically linked and allows for continuous firing, making it suitable for sustained fire operations. It can be used in various configurations, including being fed from a disintegrating link belt that can be housed in a soft pack or a hard can.

While the other options might suggest alternative feeding methods, they do not accurately represent the M240B's standard ammunition feeding system. The 500-round drum, 100-round bandoleer, and 150-round canister are either not applicable or do not fit the operational use or design of the M240B. Therefore, the 200-round belt is critical in ensuring efficient operation and effectiveness in the field.