Question 2 4 pts Given the command line: ./a.out in.dat out.dat which statement will correctly open the file in.dat within the following main function? int main(int argc, char *argv[]) { 1/statement to open file goes here return 0; 3 ifstream fin(argc); ifstream fin(in.dat); O ifstream fincargv[args]); afstream fincargv[1]); itstream fin(argv[21)