单选题 以下程序的输出的结果是( )。#include ＜iostream.h＞int x=3;void main(){ void incre(); int i; for (i=1;i＜x;i++) incre();}Void incre(){ static int x=1; x*=x+1; cout＜＜x＜＜"";}