The testis is the primary sex organ in males. Each testis has 250 testicular lobules. Each lobule has 1-3 highly coiled seminiferous tubules. These seminiferous tubules open into the vasa efferentia through rete testis. The vasa efferentia opens into the epididymis which continues to form the vas deferens. 
Vas deferens transfers the sperms mixed with semen to the ejaculatory duct.
So the correct answer is D.