Answer :
Final answer:
A muzzleloader can be safely fired with black powder or a black powder substitute because smokeless powder burns at a higher pressure, which is dangerous for muzzleloaders.
Explanation:
The question revolves around the safe operation of a muzzleloader, which is a type of firearm. A muzzleloader can be safely fired with A. Black powder or a black powder substitute. These propellants have a lower combustion rate suitable for the design of muzzleloaders.
In contrast, B. Smokeless powder is not safe for use in muzzleloaders as it burns at a much higher pressure, which can lead to damaging the firearm or causing injury to the user.