Colonial Subaru, a car company with its central office in CT$,$ facilitates various payment methods, including cash and credit$/$debit cards. Financial processes, including billing and management functions, are centralized at the corporate headquarters.

At the dealership, customers present their selected vehicles for purchase and choose their preferred payment method, whether it be cash or a credit$/$debit card. Sales representatives document the transactions, and the details, irrespective of the payment method, are entered into the dealership's point$-$of$-$sale system. At the close of each shift, the sales representative submits the transaction details to the dealership cashier. $($Cash handling procedures are not discussed here.$)$ The cashier organizes the transaction slips into batches and sends them to the corporate cash receipts department in the central office by $5$:$00$ p$.$m$.$ daily.

As transactions are recorded by the sales representatives, Colonial Subaru's central computer system captures and stores the sales data on a designated disk referred to as "sales event data." Every night, the computer generates a comprehensive sales report, summarizing the sales events data from each dealership. The subsequent morning, this sales report is transmitted to the cash receipts department.

In the cash receipts department, reconciliation takes place between the transaction slips received and the corresponding totals for each dealership outlined in the sales report. Following reconciliation, the slips are then forwarded to Colonial Subaru's IT division. Within the IT division, data preparation clerks process the slips, documenting the charges on a disk referred to as "credit sales data." At $9$:$00$ p$.$m$.$ each evening, the disk containing the credit sales data is sent to the computer room, where it is used to update the accounts receivable master data, also stored on disk.

On a monthly basis, the computer system prepares customer statements summarizing the charges. These statements are subsequently sent to customers, providing a concise overview of their transaction activity and outstanding balances with Colonial Subaru. $1.$Prepare a table of entities and activities based on the Colonial's narrative.

$2.$ Construct a context diagram of the sales and credit card billing system

$3.$ Construct a level $0$ DFD of the sales and credit card billing system