设有定义:int a=1,b=2,C=3;,以下语句中执行效果与其它三个不同的是
A.if(a>B)C=a,a=b,b=C;
B.if(a>B){e=a,a=b,b=c;}
C.if(a>B)C=a;a=b;b=C;
D.if(a>B){C=a;a=b;b=c;}
请帮忙给出正确答案和分析,谢谢!