The family ______ at the lunch table when someone came to tell them what had happened at ______.

The family ______ at the lunch table when someone came to tell them what had happened at ______.
A. were sitting; Mr BrownB. weresitting; Mr Brown’s
C. was sitting; Mr BrownD. was sitting; Mr Brown’s
主要说明 happen at下面到底加什么...谢谢``