In c programming, Write a function findLetter based on the following rules: It takes a string named str and a character named ch as parameter, returns the index of the first occurrence of the...

Extracted text: In c programming, Write a function findLetter based on the following rules: It takes a string named str and a character named ch as parameter, returns the index of the first occurrence of the character ch if the str string contains the character ch; If the relevant character is not found in the string, write a function that returns -1. Call the function inside the main function and test it. You should use the prototype given below: int findLetter (char str [], char ch)