Help with Boolean and invoking function on C++. I am writing a code that will accept three conditions: upper case, lower case, and a string that contains the acceptable letters. I also need to write a boolean function that will return true/false and isValidOption() function get invoked by getMainOption() but I am confused on how to do that. The instructions are...

How do I create bool isValidOption(), void getMainOption() that invokes isValidOptions, and then write it under int main()? Please help me!!

The menu options are: Display the inventory list - Make an Order List Orders made Exit The menu asks the user to enter an option. The user should be able to enter any string for the option. The first character of the string entered is upper-cased and used as the option. Examples: IList our Inventory 0 - Make an Order LList all Orders made xExit Enter an option: what option? Invalid option, enter I. 0. L or ! Enter an option: try again? Invalid option, enter I. 0. L or X! Enter an option: ok this will work Enter an option: converted to O and accepted Enter an option: only first character o is capitalized to O and accepted When an invalid option is entered, the program prints Invalid option, enter I, 0, L or X! repeats the input until a valid option Is entered