Final answer:
The document that indicates to the customer the amount of a sale and payment due date is the sales invoice. It provides detailed transaction information and payment terms, and is a formal request for payment.
Step-by-step explanation:
The correct document used to indicate to the customer the amount of a sale and payment due date is the A) sales invoice. A sales invoice is a document issued by a business to a customer, detailing the products or services provided, their prices, the total amount due, and the payment terms, including the due date. It's an essential document for both accounting and record keeping, as it acts as a formal request for payment and becomes part of the financial records of both the buyer and the seller.
Other documents listed such as B) bill of lading, C) purchase order, and D) sales order serve different purposes. The bill of lading is used for the shipment of goods, the purchase order is issued by the buyer to the seller specifying the goods or services they agree to purchase, and the sales order is an internal document of the seller recording the customer's request for goods or services before the invoice is created.