How did the District of Columbia obtain the ability to play a role in the presidential selection process?

A) The original wording of the constitution recognized District of Columbia as a state.
B) The District of Columbia became a state in 1961 and, as a result, gained electoral votes.
C) The U.S. Constitution was amended to include the District of Columbia in the electoral college.
D) The District of Columbia's representatives in the U.S. House and Senate introduced legislation to make the change.
E) A federal law was created that extended the right to vote to citizens of the District of Columbia.

C