问题

There _____ a lot of coal mines in the south, but many of them have been closed or are _____ be closed.
A:use to having; about to
B:used to be; to
C:use to having; going to
D:used to be; supposed to
B:used to be; to
C:use to having; going to
D:used to be; supposed to
正确答案是: