Question

what is the primary purpose of surface metal raceways?
to carry power, lighting, telephone or signal wires underground
to carry power, lighting, telephone or signal wires across a ceiling
to carry power, lighting, telephone or signal wires in outdoor locations
to carry power, lighting, telephone or signal wires by embedding them into the floor

Explanation:

Surface metal raceways are used to protect and route wires. They are often installed on surfaces like ceilings to carry power, lighting, telephone or signal wires. They are not for underground, outdoor - only, or floor - embedding use primarily.

Answer:

to carry power, lighting, telephone or signal wires across a ceiling