3.1 Identify the DFD elements in the following narrative: A customer purchases a few items from a local grocery store. Jill, a salesclerk, enters the transaction in the cash register and takes the customer's money. At closing, Jill gives both the cash and the register tape to her manager. 3.3 Compare the guidelines for preparing flowcharts, BPDs, and DFDs. What general design principles and limitations are common to all three documentation techniques