Which hormone is primarily responsible for the development of secondary sexual characteristics in boys?

Testosterone is the hormone responsible for the development of secondary sexual characteristics in boys. During puberty, increased levels of testosterone lead to physical changes such as growth of facial and body hair, deepening of the voice, increased muscle mass, and changes in body fat distribution. This hormone is crucial in driving the maturation of male reproductive organs and the development of features that are characteristic of male puberty.

In contrast, estrogen and progesterone play significant roles in female development and reproductive health rather than in the male context for secondary sexual characteristics. Oxytocin, while important in various physiological and psychological processes, including social bonding and childbirth, does not have a direct role in the development of secondary sexual characteristics in boys. Thus, testosterone is correctly identified as the key hormone in this process.