Distinguish among the sales, billing, and accounts receivable departments. Why cant the sales or accounts receivable departments

Question:

Distinguish among the sales, billing, and departments. Why can’t the sales or departments prepare the bills?
Accounts Receivable
Accounts receivables are debts owed to your company, usually from sales on credit. Accounts receivable is business asset, the sum of the money owed to you by customers who haven’t paid.The standard procedure in business-to-business sales is that...