单选题：以下函数形式中，正确的是()‎Aintfunc(intx，inty){z=x+y;returnz;}Bfunc(intx，y){intz;z=x+y;returnz;}Cfunc(x，y){intx，y;intz;z=x+y;returnz;}Dintfunc(intx，inty){intz;z=x+y;returnz;}