Think in terms of supportability first. Choose A. Developer pro sandbox. In Salesforce terms, this is a sandbox strategy issue. Sandbox selection balances data copy, refresh cadence, isolation, testing depth, and cost. Smaller sandboxes fit independent build work; larger sandboxes fit integration and production-like testing.
The selected configuration is the professional answer because it is native, declarative, and placed at the right scope. If the requirement later expands, another administrator can inspect the same metadata area and understand how the behavior is being produced. That is far better than a solution that depends on hidden assumptions or user training.
The remaining answers do not control the same Salesforce behavior. B (Partial sandbox) does not fit cleanly; Deployment tooling moves or validates metadata; it does not create the runtime business behavior itself. C (Developer sandbox) is only a partial match because Deployment tooling moves or validates metadata; it does not create the runtime business behavior itself. D (Full sandbox) misses the mark because Deployment tooling moves or validates metadata; it does not create the runtime business behavior itself. The result is a cleaner app design because the behavior is handled by the feature Salesforce built for that purpose.
For sandboxes, the builder should match the environment to the work: isolated configuration, collaborative testing, data-dependent testing, or production rehearsal.
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