On what line(s) would we need to place delete y; to prevent all memory leaks while preserving the behavior of the code? int x = 7; 2 int* y = &x; 3 4 y = new int(7); 7 8 9 10 std::cout < < y < < std::endl; y = new int(8); std::cout < < y < < std::endl; 11