问题

How do you keep in touch with your friends— We ____________ write to each other, but we _________ chatting on QQ now.
A:are used to; used to
B:used to; are used to
C:were used to; are used to
D:used to; used to;
B:used to; are used to
C:were used to; are used to
D:used to; used to;
正确答案是: