Which of the following describes the firing mode of the M4?

The M4 carbine is a versatile weapon known for its capability to operate in both semi-automatic and fully automatic firing modes. In semi-automatic mode, the weapon fires one round each time the trigger is pulled, requiring a separate trigger pull for each shot. This mode allows for greater control and accuracy, making it ideal for precision shooting scenarios.

In fully automatic mode, the M4 can continuously fire rounds as long as the trigger is held down, allowing for a high rate of fire. This feature is particularly useful in combat situations where suppressive fire may be necessary. The combination of these two modes provides soldiers with flexibility based on the tactical needs of their missions, making ensuring appropriate response in various combat scenarios.

The other choices imply limitations that do not represent the full capabilities of the M4. For instance, stating that the M4 fires only in one mode fails to acknowledge its full functionality and adaptability in the field.