Question

where should materials never be stacked or stored?
○ on scaffolds
○ outdoors
○ on pallets
○ in cabinets

Explanation:

Scaffolds are temporary structures for working at heights, and stacking materials on them can cause instability, collapse, or safety hazards. Storing outdoors (with proper precautions), on pallets (standard for storage), or in cabinets (organized storage) is generally acceptable, but scaffolds are not designed for material storage.

Answer:

A. on scaffolds