Which safety feature blocks the trigger on the M4/M16 family?

• A. M4/M16 applied safety
• B. Fire selector
• C. Grip safety
• D. Bolt catch

Answer: (C)

The safety concept being tested is how a grip-based mechanism can physically block the trigger until the shooter has a proper grip. On the M4/M16 family, a grip safety is located in the pistol grip and must be squeezed to depress it before the trigger can move enough to release the sear and fire. This design helps prevent discharge if the weapon is not being held correctly or is mishandled. The other mechanisms have different roles: the applied safety (the safety selector) stops firing by preventing the trigger/hammer from cycling, but it isn’t a grip-pressing block the way a grip safety is; the fire selector mainly sets firing mode. The bolt catch simply holds the bolt open and isn’t a safety that blocks trigger action. So, the grip safety is the feature that directly blocks the trigger unless the shooter maintains a proper grip.