Which of the following locations is it illegal to carry a firearm in Utah?

There may be a misconception that private residences, state parks, and bars are locations where carrying a firearm is illegal in Utah, but that is not the case. In fact, state law permits the carrying of firearms in state parks and private residences with the consent of the owner. However, it is illegal to carry a firearm in any federal facility in Utah, including federal courthouses, post offices, and national parks. Therefore, option C is the correct answer as carrying a firearm in a federal facility is prohibited by law in the state of Utah.