What does a 'tan accelerator' product do?

A 'tan accelerator' product is specifically designed to enhance melanin production during UV exposure, which is why the answer is B. When using a tan accelerator, the active ingredients work to stimulate the skin's natural tanning process. Melanin is the pigment responsible for giving skin its color, and increased production of melanin leads to a deeper and more even tan.

Unlike options that suggest reducing UV exposure or eliminating the need for tanning, tan accelerators are meant to be used in conjunction with UV exposure, whether from the sun or tanning beds. They do not limit their effectiveness to natural sunlight alone but can also be effective under artificial UV light sources typically used in tanning salons.