What is the primary difference between direct tanning and indirect tanning?

The primary difference between direct tanning and indirect tanning revolves around the source and method of exposure to UV rays, as indicated in the correct answer. Indirect tanning typically involves methods such as using tanning lotions or self-tanners that do not directly expose the skin to UV radiation, allowing for a gradual development of color without the immediate effects of sunlight or tanning beds. This method may involve the application of products that enhance the skin's pigmentation through chemical reactions rather than through direct UV radiation.

In contrast, the other choices misinterpret the processes involved. For instance, the concept of direct tanning used in the incorrect options often emphasizes either solely exposing the skin to UV rays or suggests that direct tanning does not use UV rays at all, which does not clarify the distinction effectively. Understanding that indirect tanning can include both the use of products and natural sunlight with protective measures helps clarify how different methods impact tanning outcomes.