What is the requirement for firearms dealers in Iowa regarding background checks?

In Iowa, the law requires all firearms dealers to conduct background checks on all sales, regardless of where the sale takes place (such as at a gun show or in a store) or what type of firearm is being sold (handguns, rifles, shotguns, etc.). Options A, C, and D are incorrect because they suggest that background checks are not required in certain situations or for certain types of firearms, which is not true in Iowa.