Which of the following statements regarding transport networks is/are true?

A. The U.S.A. has the most extensive road and air transport networks in the world.
B. The Rhine Waterway in Europe is the most heavily used inland waterway.
C. The Trans-Canadian Railway plays a significant role in connecting agricultural and industrial regions within Canada.
D. The Panama Canal shortens the sea route between New York and San Francisco by nearly 8000 km.