Northern Trail Outfitters needs to present shipping costs and estimated delivery times to its customers. Shipping services used vary by region and…

Enterprise Service Bus (ESB) is the appropriate integration pattern for this scenario. ESB provides service routing capabilities to determine which shipping service to use based on region, and message transformation capabilities to convert requests to each service's required format. This addresses the need for handling multiple shipping services with varying parameters while presenting a unified interface to the customer-facing application. ESB acts as an intermediary layer that abstracts the complexity of multiple backend services.

A. Apex REST Service would require custom coding for each shipping service integration and transformation logic, creating tight coupling and maintenance overhead.

C. ESB is a middleware integration layer, not a user interface component for collecting form data.

1. Salesforce Integration Architecture Designer Study Guide, Chapter 4: Integration Patterns, pp. 87-92 - ESB Pattern for Service Routing

2. Salesforce Platform Developer II Certification Guide, Section 3.4: Integration Patterns and Best Practices, pp. 156-161

3. Trailhead Module: "Integration Architecture on Salesforce Platform" - Enterprise Integration Patterns section

4. Salesforce Technical Library: "Integration Patterns and Practices" (Doc ID: SF-INT-PATTERNS-2023), Section 5.2: Message Routing Patterns

5. Force.com Enterprise Architecture, Second Edition, Chapter 12: Integration Strategy, pp. 342-348 - Service Abstraction Patterns