The director of customer service at Northern Trail Outfitters (NTO) wants to capture and trend specific business events that occur in Salesforce in…

This scenario requires a real-time, scalable, and decoupled integration to send business event data to an external analytics system. Platform Events are the ideal Salesforce feature for this, creating a durable event stream that external subscribers can consume in real-time.
Option C correctly addresses the events initiated by a customer creating a Case (e.g., for an exchange or cancellation). An Apex trigger on the Case object is the standard mechanism to react to record creation and can publish a Platform Event to the event bus.
Option D correctly addresses the events initiated by a service representative clicking a specific UI element. The most direct way to capture this user interaction is via the custom Apex controller backing the UI element (e.g., a Lightning Web Component), which can then publish the corresponding Platform Event.

1. Platform Events Developer Guide: "Use platform events to connect business processes in Salesforce and external apps through the exchange of real-time event data...Publish event messages from Salesforce apps using declarative tools or programmatically with Apex or APIs. Subscribe to platform events in Salesforce using Apex triggers or in an external app..." This supports using Platform Events for real-time integration with external systems.

2. Apex Developer Guide

"Triggers" section: "Triggers enable you to perform custom actions before or after events to records in Salesforce

such as insertions

updates

or deletions." This confirms a trigger is the correct tool to react to the creation of a Case (Option C).

3. Apex Developer Guide

"Publish Platform Events" section: "To publish event messages

you call the EventBus.publish method... You can call this method in Apex code that you expose as a custom action in a Lightning component

for example." This directly supports using an Apex controller to publish an event from a UI action (Option D).

4. Salesforce Well-Architected - Event-Driven Architectures: This framework advocates for event-driven patterns for asynchronous processing and system integration. It states

"Decoupling systems using events allows them to evolve independently... This pattern is ideal for broadcasting state changes to many interested systems." This validates the architectural choice of Platform Events over point-to-point callouts or outbound messages.