When a contractor company provides aggregate hours rather than a list of named technicians, the correct model is a Capacity-Based Resource so the engine schedules against capacity in hours, not against a specific individual.

Option A is correct. A Capacity-Based Resource lets you express '20 hours per day' as capacity, assign Operating Hours of 9:00 AM--5:00 PM that match the contractor's agreed window, and add the 'maintenance' skill to restrict the type of work routed to them.

Option B is incorrect because preferring contractors is a soft preference; it does not enforce the contractor's distinct hours or capacity.

Option C is incorrect because creating a separate Service Territory does not, by itself, model contractor capacity or restrict the work type assigned.

Option D is incorrect because a Named Resource represents a single person, not a company providing aggregate hours, and the Designated Work approach does not capture the daily capacity cap.