Question

what should you use to clean metal contacts (like those found on expansion cards)?
denatured isopropyl alcohol
compressed air
cleaning solvent
damp cloth

Explanation:

Denatured isopropyl alcohol is commonly used to clean metal contacts as it evaporates quickly, leaves no residue, and can effectively remove dirt, grease, and oxidation. Compressed air is mainly for blowing away dust, a cleaning solvent may leave residues or be too harsh, and a damp cloth can leave moisture which may cause corrosion.

Answer:

Denatured isopropyl alcohol