C++ ----------

Question 2 Use a switch statement to write the following program The program prompts the user for a letter grade (of type char). The list of valid letter grades is: AB D E The program should properly handle both lower and upper case as valid input. The program will then display the following messages: For grade A" display "Excellent" For grade b': display "Good" For grade 'C': display "Average" For grade 'd' or 'E': display "Below Average" For grade 'F': display "Fail" For any other letter grade entered by users: display "Invalid Grade" Your test plan should include tests for each possible output, invalid input, and upper and lower case letters