Final answer:
Androgens, particularly testosterone and androstenedione, are the class of sex hormones responsible for the development of male sex organs and secondary sexual characteristics.
Step-by-step explanation:
The sex hormones that promote the development of male sex organs are known as androgens. The primary androgens, testosterone and androstenedione, not only control the development of the male genital organs and the production of sperm but also influence secondary sexual characteristics such as facial hair, a deep voice, and muscle strength. They are secreted by the gonads (testes), the placenta, and the adrenal glands. Although both males and females produce androgens, it is the higher quantity in males that leads to the expression of male secondary sexual characteristics.