A team uses Copilot to modernize a synchronous file-processing component. Which request best supports a controlled modernization?

1. Preserve the observable contract, identify the legacy dependencies, and propose incremental changes with compatibility tests.
2. Replace all dependencies with current alternatives and infer any new behavior from their defaults.
3. Generate only a new README describing the component as modernized.
4. Rewrite the entire service using a different language without checking deployment support.