Here, we have created an options_description object called "desc" and added two options to it. The first option is a string option with name "input" and a help text "input file". The second option is also a string option with name "output", a default value "output.txt" and help text "output file". Another example of using options_description is to generate a help message for the program. This can be done by calling "desc" object's "print" function:c++ std::cout << desc << std::endl; ``` This will output the description of the available options for the program. Overall, Boost.program_options is a C++ package library that provides a wide range of functions to parse command-line options. It is a part of the Boost C++ libraries.