Which of the following sentences is punctuated correctly?
A.
The capital of the United. States. is Washington D.C. located on the East Coast.
B.
The capital of the United States is Washington, D.C., located on the East Coast.
C.
The capital of the United States is Washington, D.C. located on the East Coast
D.
The capital of the United States is Washington D.C., located on the East Coast