To remove acrylic nails safely, one should soak them in which of the following substances?

Soaking acrylic nails in acetone is the recommended method for safe removal. Acetone is a powerful solvent that effectively breaks down the acrylic material, allowing for easier removal without damaging the natural nail beneath. When acrylic nails are soaked in acetone, the chemical reaction softens the acrylic, enabling it to be gently scraped away or pushed off without excessive force or risk of injury.

Other substances listed, such as soap and water, alcohol, and hydrogen peroxide, do not possess the same effectiveness in breaking down acrylic nails. Soap and water may help in cleaning, but they do not dissolve acrylic. Alcohol can be used for sanitizing, but it lacks the solvent properties necessary to effectively remove acrylic. Hydrogen peroxide, while useful as an antiseptic, similarly does not have the capability to break down acrylic materials. Therefore, using acetone is the most appropriate and safe choice for removing acrylic nails.