--Could you tell me ______________  for class this morning?

--I am sorry, Mrs. Lin. I got up so late that i couldn’t catch the first bus.

A．why were you late

B．why you are late

C．why are you late

D．why you were late

经测试发现某软件系统存在缓冲区溢出缺陷，针对这一问题，最可靠的解决方案是（）。

A.更改防火墙设置

B.对软件系统自身进行升级

C.安装防病毒软件

D.安装入侵检测系统