Final answer:
In reproduction, only males produce sperm (option A). Both males and females produce hormones and DNA, but sperm production is unique to males and occurs in the testes through spermatogenesis.
Step-by-step explanation:
In reproduction, only males produce sperm. Sperm are the male gametes that are necessary for fertilization with female gametes, or eggs. Both males and females produce hormones and DNA, which are common to all human cells. However, the production of gametes is sex-specific: males produce sperm and females produce eggs. Sperm are produced by the testes through a process called spermatogenesis, where each sperm cell contains half the amount of DNA found in regular body cells, making them haploid cells with 23 chromosomes. At fertilization, a sperm cell unites with an egg, combining genetic material to form a new organism with a full set of chromosomes.
Hence, the answer is option A.