Question

what protective device is required for a floor opening that measures at least 12 inches in its least dimension? a guardrail or cover a warning sign a step or steps to the lower surface employee notification

Explanation:

For floor openings that measure at least 12 inches in their least dimension, a physical barrier like a guardrail or cover is needed to prevent falls and other accidents. A warning sign, steps, or employee notification are not sufficient protective devices compared to a guardrail or cover.

Answer:

A. A guardrail or cover