Which structure carries both sperm and urine out of the body?

The structure that carries both sperm and urine out of the body is the urethra. The urethra serves a dual purpose in males, functioning as a conduit for urine from the bladder and also transporting sperm from the reproductive system during ejaculation. This anatomical feature is essential for the male reproductive and urinary systems, allowing the expulsion of both fluids through a single pathway.

In contrast, the ureter specifically transports urine from the kidneys to the bladder and does not play a role in sperm transport. The vas deferens is responsible for carrying sperm from the epididymis to the ejaculatory duct but does not handle urine. Lastly, the epididymis is involved in the maturation and storage of sperm, but it does not have a function in transporting urine. Understanding the functions of these various structures highlights why the urethra is the correct choice for this question.