Which structure is cut during a vasectomy?

The vas deferens is the correct structure that is cut during a vasectomy. This procedure is designed to provide a surgical means of male contraception by preventing sperm from mixing with semen during ejaculation. The vas deferens is a muscular tube that transports sperm from the epididymis to the urethra. When it is cut and sealed, sperm can no longer travel through this pathway, effectively preventing fertilization.

This makes the vas deferens vital in the male reproductive system, as cutting it directly impacts sperm transport. The other structures listed—urethra, epididymis, and seminal vesicle—serve different functions in the reproductive process and are not the target of this procedure. The urethra is responsible for transporting urine and semen outside the body, the epididymis stores and matures sperm, and the seminal vesicle contributes fluid to semen production, but none of these structures are involved in the cutting performed during a vasectomy.