Salesforce Knowledge can be related directly to the Work Order object so that articles surface alongside the job a technician is performing, both on desktop and in the Field Service Mobile App.

Option C is correct. 'Knowledge on Work Orders' allows the admin to attach Knowledge Articles to Work Orders and Work Types. Technicians can read step-by-step procedures, troubleshooting guides, and reference material directly from the related Work Order on the Field Service Mobile App, which is exactly the experience needed in the field.

Option A is incorrect because Custom Links typically open external URLs and require connectivity. They do not provide a managed library of articles.

Option B is incorrect because Knowledge on Cases is a Service Cloud feature for case handling, not for field technicians who work from Work Orders.

Option D is incorrect because Attachments on Cases are unmanaged files associated with Cases, not curated, searchable content for technicians.