Question

mature spermatozoa leave the testes via this structure, which is cut during a vasectomy.
urethra
seminiferous tubule
ductus deferens
prostatic duct

Explanation:

Mature sperm exit the testes through the seminiferous tubules first, but the structure targeted in a vasectomy (the duct that carries sperm from the testes onward) is the ductus deferens (also called vas deferens). The urethra is the final passage for ejaculation, seminiferous tubules are where sperm are produced, and prostatic ducts carry prostate fluid, not sperm from the testes.

Answer:

Ductus deferens