Final answer:
FSH stimulates the testes in males to produce testosterone, which plays a crucial role in male reproductive functions and the development of secondary sex characteristics.
Step-by-step explanation:
In males, the hormone Follicle-stimulating hormone (FSH) stimulates the testes to produce the steroid hormone testosterone. Testosterone is responsible for the development and maintenance of the male reproductive system, the maturation of sperm cells, and the development of secondary sex characteristics such as increased muscle mass and body hair. The primary role of FSH in men is to regulate spermatogenesis, which is the process of sperm cell development, occurring in the testes.