Answer:
A) send an acknowledgment that the order has been received.
Step-by-step explanation:
Under UCC rules, contracts for the sale of products or services worth $500 or more have to be in writing and signed. Instead of a signed contract, a company can accept a written offer (e.g. by email), but it should send a written acknowledgment that the order has been received and accepted (or rejected). This way, both parties have a duty to perform.