Identify the source document for NDX Company in each of the following accounting processes. 

a. A customer purchases merchandise with a credit card. NDX uses the electronic sales receipt to record transaction details in its accounting system.

b. NDX purchases goods and receives a bill from the supplier. Details from the bill are captured and entered in the accounting database, which is stored in the cloud.

c. An NDX employee receives a bank statement each month on her company e-mail. The statement is used to record bank fees incurred for that month.