Which of the following defines secondary sex characteristics?

The correct answer identifies secondary sex characteristics as physical traits that emerge during puberty, which distinguish the sexes but are not directly linked to the reproductive system. These characteristics include features such as breast development in females, increased body hair in males, and changes in voice pitch. They develop in response to hormonal changes in the body and serve to signal sexual maturity, contributing to sexual attraction and differentiation in physical appearance.

While reproductive organs are indeed essential for sexual reproduction, they fall under primary sex characteristics, which are directly involved in the reproductive process. Biological sex determined at birth refers to the labeling of individuals as male or female based on physical anatomy, rather than the traits that develop later. Lastly, the influence of genetics alone does not account for the hormonal aspects that play a crucial role in the development of secondary sex characteristics. Thus, the focus on physical traits that arise from hormonal changes during puberty is what makes this answer accurate.