选择出合法的if语句(设int x,y;)( )。 A if(x!=y)if(x>y)printf("x>y\n”);else prinf(”x<y\n”);else printf(”X==y\n”); B if(xi=y)if(x>y)printf(”x>y\n”)else printf(”x<y\n”);else printf(”x==y\n”); C if(x!=y)if(x>y)Printf(”x>y\n”);else printf(”x<y\n”)else printf(”x==y\n”); D if(x!=y)1f(x>y) Printf(”x>y\n”);else printf(”x<y\n”)e1se Printf(”x==y\n”);