The Proximity Explosive sticks to a surface and blows up when an enemy comes close. Use it to trap roads, doorways and patrol paths so the FND walk into their own ambush.
Stick it on a road where a convoy will pass, or on a doorway a patrol uses. It goes off by itself when someone gets close, so you can be somewhere else when it does.
C4 needs you to trigger it, which suits a planned ambush. The Proximity Explosive is better when you do not know exactly when the enemy will arrive.
Bait
Bait is a chunk of meat you throw to draw predators to a spot. Toss it near FND soldiers and let the local wildlife do the fighting, or use it to bring out animals while hunting.
C4
C4 is a remote-detonated explosive you place and trigger when the moment is right. It is your best tool for setting traps on roads, wiping out parked vehicles or blowing up a target without being nearby.
Dynamite
Dynamite is a timed explosive built for wrecking vehicles rather than soldiers on foot. Throw it under an armored car or tank and get clear before the fuse runs out.
EMP Grenade
The EMP Grenade shuts down vehicles, cameras and alarms in its blast. Throw one before you sneak into a base to blind its security, or stop a vehicle dead in its tracks.