Does an application that consumes an IBM Watson service need to be hosted on IBM Bluemix?

An application that consumes an IBM Watson service does not need to be hosted on IBM Bluemix, as it can interact with the Watson services through standard REST API calls. This means that any application framework capable of making HTTP requests and handling responses can successfully connect to and utilize Watson services, regardless of where it is hosted.

This flexibility allows developers to integrate Watson services into various environments and applications, whether they are local, on-premises, or hosted in the cloud on platforms other than Bluemix. It emphasizes the power of Watson's API-driven architecture, which is designed to be accessible and interoperable across different platforms.

The other options suggest that there are limitations or requirements related to being hosted on Bluemix, which is not the case. Watson services are accessible from any environment that supports RESTful communication, reinforcing the idea that the use of Watson is not restricted to any specific cloud infrastructure.