The correct answers are B. Apex and C. AppExchange.

Cloud Kicks needs to count related Case records on Account based on open and closed status. Standard roll-up summary fields work only in supported roll-up relationships, mainly master-detail relationships. Salesforce documentation states that lookup relationships do not support roll-up summary fields.

Because Cases are related to Accounts through a lookup-style relationship, native roll-up summary fields are not the best available option in this answer set. The app builder can meet the requirement by using:

Apex — Apex triggers can run before or after record changes such as insert, update, or delete, allowing custom logic to recalculate the open and closed Case counts on the Account.

AppExchange — AppExchange roll-up tools, such as lookup roll-up packages, can summarize records across lookup relationships without building custom code.

Why others are incorrect:

Validation Rule prevents invalid data entry; it does not calculate related record counts.

Approval Process routes records for approval; it does not summarize Case counts.

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