Read the excerpt from "The Dark Game."

"On January 16, 1917, in a clear attempt to convince the Mexican government to help Germany in the war, Arthur Zimmermann, the German foreign secretary, sent a telegram to Count von Bernstorff, the German ambassador in Washington. The foreign secretary wanted to be certain that this message reached von Bernstorff, so he made arrangements for it to be carried aboard a U-boat to Sweden and from there to Washington through diplomatic channels."

Which statement best explains how the evidence from this excerpt leads to the inference that the message Zimmermann sent was important?

A. Because Arthur Zimmermann rarely sent telegrams to von Bernstorff, the contents of the message had to be very important.
B. Because the message was so important and needed to reach von Bernstorff, Zimmermann wanted the message to be carried across the ocean in a U-boat.
C. The telegram's destination, Washington, D.C., suggests that the contents of the telegram were important to the Germans and the British.
D. The route the telegram was to take, first to Sweden and then to Washington, D.C., supports the idea that the contents of the message were important.