Explanation:

Ultraviolet waves (Option B) are commonly used to detect forgery in currency notes. Many security features embedded in banknotes, such as fluorescent fibers, watermarks, and specific inks, are designed to glow or become visible under UV light, helping to distinguish genuine notes from counterfeits. Infrared waves (Option A), Microwaves (Option C), and Radio waves (Option D) are not typically used for this specific purpose, as currency security features are not designed to react to these wavelengths in the same way.