△ABC的三个顶点的坐标分别为A（1，0）、B（3，0）、C（2，-4），将△ABC各点的横坐标都乘以-1，得到△DEF，则△DEF与△ABC的位置关系是（　　）

A．关于x轴对称

B．关于y轴对称

C．关于原点对称

D．△DEF是△ABC

The boy the teachers considered _________ was caught __________ in the exam, which surprised us very much.

A．to be the best; cheating

B．as the best student; to cheat

C．being the best; cheating

D．as a good student; to cheat