When is it lawful to use a firearm in self-defense in Utah?

In Utah, it is lawful to use a firearm in self-defense when faced with imminent danger to life or serious bodily injury. This principle is based on the concept of using reasonable force to defend oneself or others from harm. It is important to remember that the use of lethal force should only be a last resort when there is a genuine threat of death or serious injury. Therefore, option C is the correct choice as it aligns with the legal standards of self-defense in Utah.

Option A is incorrect because simply feeling threatened does not necessarily justify the use of lethal force for self-defense in Utah. Option B is incorrect because using a firearm to protect property alone is not generally considered justifiable self-defense. Option D is also incorrect as using a firearm to scare off trespassers may not meet the legal standard of imminent danger to life or serious bodily injury.