Final answer:
The 'cout' object will not be recognized if 'iostream' is not included in a C++ program. 'iostream' handles standard input and output operations, while 'main', 'std', 'namespace', and 'return' are not directly affected by this inclusion.
Step-by-step explanation:
If iostream is not included in a C++ program using the #include directive, then the cout object will not be recognized. The iostream library is responsible for input and output operations in C++ and contains definitions for the cin, cout, cerr, and clog objects, which are used for standard input and output. Without including this library, you will not be able to use the cout object, which is typically used to output data to the screen. Other parts of the language and standard library like main, std, namespace, and return are not directly affected by whether iostream is included or not.