Question

what should be ensured before attempting to lift any material?
o ensure the stacking ratio is no greater than 3.1
o look for any protruding nails, wires, or sharp edges
o use a safety harness

Explanation:

Before lifting any material, it is important to check for potential hazards like protruding nails, wires, or sharp edges to avoid injury. Checking the safety factor (first option) is more relevant in engineering - design - related contexts for structures and components, and using a safety harness is usually for working at heights rather than just general material - lifting.

Answer:

look for any protruding nails, wires, or sharp edges