A clean build puts the rule where Salesforce evaluates it. Choose C. External objects; D. Big objects. In Salesforce terms, this is a platform configuration issue. The Platform App Builder role is to choose the standard Salesforce capability that owns the behavior: data structure, access, automation, user experience, reporting, or deployment.
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. A (Related objects) would be fragile here because it could produce an inconsistent result once different users, records, or apps are tested. B (Custom objects) does not fit cleanly; it solves a symptom of the problem rather than the Salesforce mechanism that owns the result. The result is a cleaner app design because the behavior is handled by the feature Salesforce built for that purpose.
For general platform design, the strongest answer is the native feature that can be enforced, audited, and maintained through Salesforce metadata.
For general platform design, the strongest answer is the native feature that can be enforced, audited, and maintained through Salesforce metadata.
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