Answer:
B. Build-up of soil residues
Explanation:
We need to clean non-food contact surfaces every 24 hours to prevent a buildup of soil on those surfaces. Since non-food contact surfaces don't come in contact with exposed food we need to watch out for them collecting soils that can later feed bacteria or mess up the surfaces in general. This is the reason why these surfaces should be made from non-corrosive non-porose materials.
