When converting a pipeline to a JavaScript controller and needing to debug the controller in Salesforce B2C Commerce, you must set up an appropriate debugging environment that supports JavaScript controllers specifically:
* Option D: Create and use a new controller debug configuration is the correct answer. This is because the debugging tools and configurations for pipelines are different from those used for JavaScript controllers. A controller debug configuration specifically targets the debugging of server-side JavaScript, allowing breakpoints, step-through, and inspection of JavaScript code executed on the server.
Option A refers to a generic script debug configuration, which might not be specific enough. Option B and C, related to pipeline debuggers, are not applicable to JavaScript controllers, as they are designed for the older pipeline architecture.