下面哪种方式不能实现将字符串"Welcome to GESP!"输出重定向到文件log.txt （ ）。
1 freopen("log.txt", "w", stdout);
2 cout << "Welcome to GESP!" << endl;
3 fclose(stdout);
1 std::ofstream outFile("log.txt");
2 outFile << "Welcome to GESP!" << endl;
3 outFile.close();
1 std::ofstream outFile("log.txt");
2 cout << "Welcome to GESP!" << endl;
3 outFile.close();
1 ofstream log_file("log.txt");
2 streambuf* org_cout = cout.rdbuf();
3 cout.rdbuf(log_file.rdbuf());
4 cout << "This output will go to the log file." << endl;
5 cout.rdbuf(oorg_cout);