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

Testosterone is the primary hormone responsible for the development of secondary sexual characteristics in males. It plays a critical role during puberty, leading to physical changes such as increased muscle mass, deepening of the voice, growth of facial and body hair, and changes in fat distribution. Produced mainly in the testes, testosterone influences not only physical characteristics but also impacts libido and overall male reproductive health.

In contrast, estrogen and progesterone are chiefly associated with female sexual characteristics and reproductive functions. Follicle-stimulating hormone is involved in regulating the reproductive processes, but it does not directly lead to the development of male secondary sexual characteristics. Therefore, testosterone’s role as the main driver for these male-specific traits makes it the correct answer.