Read the following sentences:
“Additionally, Musk believes the Hyperloop could be completely powered by the sun—making it more environmentally friendly than cars, airplanes, or train systems. Someday it could possibly move people between the East and West Coasts of the United States in less than an hour, which is faster than any other mode of transportation that exists.”
What does the word mode mean in the sentence above?
Select one of the following: