By opening vast areas of unoccupied land for residential expansion, the omnibuses, horse railways, commuter trains, and electric trolleys pulled settled regions outward two to four times more distant from city centers than they were in the premodern era.

　　The word "vast" is closest in meaning to which of following?

　　(A) large

　　(B) basic

　　(C) new

　　(D) urban

　　正确答案： A