a. Create an application named CustomerDemo that prompts a user for data for five Customer objects, sorts them in ID number order, and displays all their data as well as a grand total of the amounts owed by all customers. The Customer class includes auto-implemented properties for a customer ID number, name, and balance due. Override the ToString() method to return all the details for a customer.

b. Using the Customer class as a base, derive a CreditCustomer class. A CreditCustomer contains all the data of a Customer, plus a field to hold a monthly interest rate. Create a program named CustomerDemo2 that contains an array of five CreditCustomer objects. Prompt the user for all the necessary data. Override the parent class ToString() method to include the child classs additional data. Sort all the records in ID number order and display them with a total amount owed from all CreditCustomers.

c. Write an application named CustomerDemo3 that uses an extension method for the CreditCustomer class. The method computes and returns a CreditCustomers monthly payment due (1/24 of the balance). The application should allow the user to enter data for five CreditCustomers and then display all the data for each

question based on C# .NET