下面哪种方式不能实现将字符串"Happy Spring!"输出重定向到文件log.txt（ ）。

freopen("log.txt", "w", stdout); 

cout << "Happy Spring!" << endl; 

fclose(stdout);

std::ofstream outFile("log.txt");   

outFile << "Happy Spring!" << endl; 

outFile.close();

std::ofstream outFile("log.txt"); 

cout << "Happy Spring!" << endl;  

outFile.close();

ofstream log_file("log.txt");

streambuf* org_cout = cout.rdbuf(); 

cout.rdbuf(log_file.rdbuf());

cout << "Happy Spring!" << endl; 

cout.rdbuf(org_cout);