Since the 1980s, it ______ possible to listen to British and American English at the flick of a switch.

Since the 1980s, it ______ possible to listen to British and American English at the flick of a switch.

1. A.
   is
2. B.
   has been
3. C.
   had been
4. D.
   was

Since the 1980s, it ______ possible to listen to British and American English at the flick of a switch.

Since the 1980s, it ______ possible to listen to British and American English at the flick of a switch.

Since the 1980s, with satellite TV and the Internet, it        possible to listen to British and American English at the flick of a switch.

A. was       B. had been       C. has been       D. was to be