问题
Do you know _______ they got to know each other? —- It was last year_______ they both taught Chinese in Scotland.
A:When it was that, when
B:when it was that, while
C:When it was that, that
D:When it was that, as
B:when it was that, while
C:When it was that, that
D:When it was that, as
正确答案是：
