Coffee stains can best be removed by

Correct Answer: A solution of borax in water

Explanation:

• Coffee stains are organic stains that are best removed by mild alkaline solutions.
• Borax solution (sodium tetraborate in water) works effectively because it is a weak alkali that breaks down the stain and helps lift it from the fabric.
• Kerosene and turpentine are better suited for greasy stains, not coffee.
• Carbon tetrachloride is used for oily stains (like grease), not for tannin-based stains such as coffee.

Therefore, coffee stains can best be removed using a solution of borax in water.