A client has a requirement to get the location of stores based on the zip...

The correct approach to implementing an OSGi service in AEM is to use the Declarative Services annotation @Component(service = Interface.class). This ensures that the OSGi container properly registers the service against its interface, making it available for injection into other services, Sling Models, or servlets. In this case, the service is required to fetch store locations from an external API. Using an HTTP client within the OSGi service is the appropriate method to manage these requests. Option A is invalid because @OSGIService is not a valid annotation for service declaration. Option C is incorrect because @Service is not an OSGi Declarative Services annotation in this context. Adobe emphasizes encapsulating external API logic in OSGi services so that components and Sling Models can consume the data in a decoupled manner. This promotes separation of concerns and reusability.