Which of the following firearms is most appropriate for hunting big game?

A .22 caliber rifle is not suitable for hunting big game because it lacks the necessary power and can lead to inhumane kills. An air rifle is also not appropriate for hunting big game as it lacks the necessary power and may not meet hunting regulations. While some may argue that all options are equally appropriate, a 12-gauge shotgun with slugs is the most commonly recommended and commonly used firearm for hunting big game due to its power and accuracy.