What should an Integration Architect do to satisfy these requirements?

Northern Trail Outfitters (NTO) leverages Sales Cloud for tracking and managing leads, accounts, contacts, and opportunities- Orders and order fulfillment is taken care of by an Order Management System (OMS) in the back-office. When an opportunity has changed it’s status to "Closed/Won" and there are products attached, the details should be passed to the OMS for fulfillment operations.

The callout from Salesforce to the OMS should be synchronous.

What should an Integration Architect do to satisfy these requirements?
A . Write a trigger that invokes an Apex proxy class to make a REST callout to the Order Management System.
B. Use Process Builder to call an Apex proxy class to make a REST callout to the Order Management System.
C. Develop a batch Apex job that aggregates Closed Opportunities and makes a REST callout to the Order Management System hourly.
D. Build a Lightning Component that makes a synchronous Apex REST callout to the Order Management System when a button is clicked.

Answer: B