How should an Architect design this requirement considering both security and scalability?

Universal Containers (UC) has an ERP application where all customer orders are stored. There are millions of customers order stored in the ERP application and a longtime customer may have thousands of individual orders. Additionally, some order information may house personally identifiable information that, due to company policy, can only be stored in ERP. UC would like the five most recent orders displayed on the account page in Salesforce.

How should an Architect design this requirement considering both security and scalability?
A . Leverage Salesforce Connect to display order information in Salesforce.
B . Write an outbound message to receive orders from ERP system as they are created.
C . Build a scheduled ETL job to sync all customer order history in the Orders object.
D . Leverage the REST API to receive orders from the ERP system as they are created.

Answer: A