Correct Answer: AWhen designing an integration to send orders from Salesforce to a fulfillment system, an important system constraint to consider is the acceptable latency for orders to reach the fulfillment system. This constraint focuses on the timely delivery of orders, ensuring that they are processed within an acceptable period, which is crucial for maintaining efficient operations and customer satisfaction. Other options, such as the validation of order shipping addresses or the implementation of a contract-first Outbound Messaging interface, are important but secondary to ensuring that the orders are transmitted promptly.