When performing a static check to determine tooth contact, you should use which of the following compounds to coat the gear teeth?

Correct Answer: Option C — Prussian Blue.

Prussian Blue is a non-abrasive, high-viscosity paste used to verify gear tooth contact patterns. When applied to the teeth, it transfers to the mating gear under static load, clearly highlighting the contact area. This allows technicians to ensure proper alignment and load distribution within the reduction gear assembly.