The answer comes from Salesforce's separation of responsibilities. Use B. Use an AppExchange solution. The selected option is not chosen because it sounds familiar; it is chosen because it gives Salesforce the right instruction at runtime. A Lightning component must be exposed for the surface where it is used. A component built for one page type or action surface does not automatically become available everywhere in Lightning Experience.
The scenario describes a business outcome, not merely an administrative preference. If the feature is configured correctly, users get the intended result without depending on memory, spreadsheets, or manual policing. That is the professional standard for Platform App Builder work: place the rule in metadata, test it under the correct permissions, and keep the design supportable.
The alternatives are plausible only if the requirement is read too narrowly. A (Build a screen flow page.) should be rejected because Flow is broad, but it is not correct unless the requirement is specifically about guided or automated logic. C (Build a Lightning record page.) does not fit cleanly; A Lightning component changes the interface; it does not automatically solve security, relationship, or data-quality requirements. D (Use a Bolt solution.) is only a partial match because it does not provide the same direct administrative control as the selected option. A complete implementation should also check page assignment, field access, record ownership, and mobile behavior where those factors apply.
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