How can an automation service that was created outside IBM Business Automation Studio be used?

The correct answer is C. IBM Business Automation Studio supports reuse of services that were created outside Studio through external automation services. External automation services allow reuse of existing services created outside IBM Business Automation Studio. Existing process applications from traditional Business Automation Workflow can be reused by importing them and creating an automation service in Business Automation Studio, or services can be discovered from an OpenAPI or Swagger file and selected for publication as external automation services. Once published, these services become discoverable and reusable by applications and other automations through the Business Automation Studio catalog. Option A describes a configuration-file approach that is not the documented primary flow. Option B is too narrow because HTTP method definition alone does not cover the external automation-service lifecycle. Option D describes only part of a service-description concern and omits creation and publication as an external automation service. References/topics: Business Automation Studio, external automation services, OpenAPI/Swagger services, traditional BAW process application reuse, publishing automation services.