Given that the decision states, DC is not a state, where did "C) DC is a State", come from?
The the article said, "The majority opinion also rejects the argument that the Second Amendment does not apply to the District of Columbia because it is not a State."
Leaving me, therefore, to conclude that they considered DC a "state" for this ruling. (ie., the ruling applies to the states, we reject the argument that the ruling doesn't apply to DC, ergo, DC is a state).