These headlines speak about the law on the sale and carrying of firearms, as well as the legality of the existing Gun Control Law. Gun control is a set of laws that regulate the production, sale, transfer, possession and use of firearms. According to Second Amendment of the Constitution that the well-regulated militias necessary for the security of the free State, as well as the right of the people to guard and carry weapons, will not be infringed. While any other law that infringes the operational clause of the amendment, violates it. So all these headlines represent a debate about the Second Amendment.
The answer is: D.