Resolve with C$++$

Redo Programming Exercise $16$ of Chapter $4$ so that all the named constants are defined in a namespace royaltyRates.

Instructions for Programming Exercise $16$ of Chapter $4$ have been posted below for your convenience.

Exercise $16$

A new author is in the process of negotiating a contract for a new romance novel. The publisher is offering three

options. In the first option, the author is paid $$5,000$ upon delivery of the final manuscript and $$20,000$ when the novel

is published. In the second option, the author is paid $12\mathrm{.}5\%$ of the net price of the novel for each copy of the novel

sold. In the third option, the author is paid $10\%$ of the net price for the first $4,000$ copies sold, and $14\%$ of the net price

for the copies sold over $4,000.$ The author has some idea about the number of copies that will be sold and would like

to have an estimate of the royalties generated under each option. Write a program that prompts the author to enter

the net price of each copy of the novel and the estimated number of copies that will be sold. The program then

outputs the royalties under each option and the best option the author could choose. $($Use appropriate named

constants to store the special values such as royalty rates and fixed royalties.$)$