单项选择题

如下程序运行时的输出结果是 #include<iostream> using namespace std; class ONE{ int c; public: ONE( ):c(0){eout<<1;} ONE(int n):C(n){cout<<2;} }; class TW0{ ONE onel; ONE one2; public: TWO(int m):one2(m){eout<<3;} }; int main( ){ TWO t(4); return 0; }

A.3
B.23
C.123
D.213