The bank offers the following types of accounts to its customers: saving accounts, checking accounts and money market accounts. Customers are allowed to deposit money into an account (thereby increasing its balance), withdraw money from an account (thereby decreasing its balance) and earn interest on the account. Each account has an interest rate Assume that you will write the code for an application that will calculate the amount of interest earned for a bank account.

a. Identify the potential classes in this problem domain be list all the nouns
b. Refine the list to include only the necessary class names for this problem
c. Identify the responsibilities of the class or classes.