Mapping resources to specific Zip Codes (which are not necessarily Service Territories) is a common high-volume requirement.

Option A is correct. Creating a standard Service Territory for every postal code (Option D) creates a hierarchy that is too deep and hurts performance.

Instead, modeling "Zip Code Coverage" as a Custom Object (or data table) allows for a cleaner data model. You then use the Extended Match Work Rule . This rule is highly flexible; it can verify that the Zip Code on the Service Appointment matches a record in the Zip Codes Covered related list on the Service Resource. This supports optimization without bloating the Territory or Skill tables.

Option B (Match Fields) only works for 1-to-1 matching (e.g., The Resource has one zip field). It cannot easily handle a resource covering 50 different zip codes unless you use the custom object approach described in A.