From the narratives below create a level zero data flow diagram.

The Bbo Co. Service offers variety of telephone, in-office, and in-home computer services.
When a call for assistance comes into their Bbo number, the Bbo Co. determines  its geographical origin and routes the call to an agent in the area. The agent confers with  the customer by phone, determining the nature of the problem and the type of service  desired. The agent also will find out if the customer has previously done business with Bbo Co. Service. The agent will respond to the costumer’s request and report the problem’s  resolution to the corporate office. The corporate office bills the customer and collects  payment; a fixed fee is remitted to the local agent based on the type and nature of the  service call.