What are secondary sex characteristics?

Secondary sex characteristics refer to the features that emerge during puberty that are not directly involved in reproduction but distinguish the two sexes. These characteristics typically develop under the influence of sex hormones—such as testosterone in males and estrogen in females—and include traits like body hair, breast development, voice changes, and changes in body fat distribution.

The correct choice emphasizes that these traits are nonreproductive sexual characteristics, which aligns with the definition of secondary sex characteristics. In contrast, reproductive organs and structures pertain more to the primary sexual characteristics that are directly involved in the reproductive system. Additionally, primary sexual traits are present at birth and include organs like the ovaries and testes, while childhood developmental traits do not specifically pertain to sexual characteristics at all.

Thus, focusing on the nonreproductive aspect makes the provided answer accurate in context with the definition of secondary sex characteristics.