Final answer:
2) Rubbing alcohol. is the best option for dissolving built-up grime on a sewing machine because it is effective at cutting through grease and oils without leaving a residue.
Step-by-step explanation:
The correct answer is option 2) Rubbing alcohol. Rubbing alcohol is an effective solvent for cleaning off grime from a sewing machine. Its organic, water-miscible properties make it a suitable choice for dissolving oils and greases that can accumulate on machinery.
Unlike soap and water, which may not be as effective with hard water or heavy grease, rubbing alcohol can cut through grime without leaving a residue. Vinegar is also a cleaning agent but might not be as effective on oily substances, and bleach might be too harsh and can cause damage or discoloration to your sewing machine.
When using rubbing alcohol, it is important to make sure the machine is unplugged and you avoid getting any liquid on electrical parts.