Passage: The first emergency chocolate ration bar commissioned by the United States Army was the Ration D, commonly known as the D ration. Army Quartermaster Colonel Paul Logan approached Hershey's Chocolate in April 1937, and met with William Murrie, the company president, and Sam Hinkle, the chief chemist. Milton Hershey was extremely interested in the project when he was informed of the proposal, and the meeting began the first experimental production of the D ration bar.

Question: What is the Ration D otherwise know as?
the D ration