To build a maintainable and scalable solution, a developer must separate business logic from trigger execution and avoid hard-coding threshold values.

First, the $1,000,000 threshold should be stored in Custom Metadata (Option B). Custom Metadata is superior to hard-coding or even Custom Settings in this context because the records are deployable and can be queried efficiently without counting against standard SOQL limits. If the business decides to lower the "high value" threshold to $500,000, an administrator can simply update the Custom Metadata record without requiring any code changes or redeployments.

Second, the logic to identify these opportunities should be moved to a Helper Class (Option D). This follows the "Separation of Concerns" principle. Instead of writing the SOQL query and logic inside the trigger, the trigger calls a method in the helper class. Similarly, the Lightning Web Component's Apex controller can call the exact same method in the helper class. This ensures that the definition of a "high value opportunity" is managed in one single place in the codebase. If the logic becomes more complex (e.g., adding Industry filters), the developer only needs to update the helper class once to satisfy both the trigger and the UI component. Option A leads to "spaghetti code," and Option C is impossible as triggers cannot be called directly from JavaScript or other Apex classes.

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