Which combination of items should be placed under furniture to prevent rust staining on the carpet?

Using plastic and foil tabs under furniture is effective in preventing rust staining on carpets for several reasons. First, the plastic components create a barrier that helps to isolate moisture, which is often a contributor to rust formation. Since furniture can retain moisture, especially in environments that are humid or have spills, the plastic effectively prevents direct contact with the carpet, reducing the risk of rust transferring onto the fibers.

The foil tabs serve an additional purpose: they reflect moisture away from the furniture's metal components. Metals in contact with moisture can lead to rusting, so the reflective surface of the foil helps to keep the area dry by not allowing moisture to settle or be absorbed by the underlying materials.

Other combinations, while they may provide some level of protection, do not offer the same assurance. For example, wood blocks alone might be prone to absorbing moisture over time, and materials like cardboard might degrade or absorb moisture, making them less effective for long-term use under furniture. Plastic and foil tabs, however, are specifically designed to handle moisture, making them the ideal choice to prevent staining from rust.