以下运用if语句判断x和y大小的程序段，错误的是

• A.if (x>y) printf(" x>y ");
  
  if (x<y) printf(" x<y ");
  
  else printf(" x=y ");

• B. if(x>=y)
  
  if(x>y) printf("x>y");
  
  else printf("x=y");
  
  else printf("x<y");

• C.if (x>y) printf(" x>y ");
  
  if (y>x) printf(" x<y ");
  
  if (x==y) printf(" x=y ");

• D.if (x>y) printf(" x>y ");
  
  else if (x<y) printf(" x<y ");
  
  else printf(" x=y ");