Which of the following changes occur in males during sexual maturity?

The correct choice highlights a significant physiological change that occurs in males during sexual maturity. During puberty, males experience a surge in testosterone levels, which plays a crucial role in the growth and development of both external and internal genitalia. This includes the enlargement of the penis and testicles, as well as development of secondary sexual characteristics, such as increased muscle mass and body hair.

While some of the other options might relate to general adolescent development, they do not accurately reflect the typical changes associated with male sexual maturation. For instance, males do not typically experience a wider hip structure as part of their maturation. Instead, they may develop broader shoulders, which is more aligned with male physical development during adolescence. Additionally, while a decrease in body fat percentage can occur, it is not as direct or universally applicable as the growth of genitalia. Increased vocal range is misleading as males usually experience a deepening of the voice, leading to a lower range rather than an increase in range. Thus, the growth of external and internal genitalia is the most definitive and defining change occurring in males during sexual maturity.