Which of the Following Is True in the Mapping and Exploration

 Which of the following is true in the mapping and exploration of North America?

A) Captain Cook's Pacific journey helped establish the dimensions of the North American continent.
B) George Vancouver charted the American western coast as far north as Alaska.
C) Alexander Mackenzie crossed the entire American continent by foot east to west.
D) The journey of Lewis and Clark applied a universal grid from the Mississippi to the Pacific coast.
E) All of the answers are correct.