Male Reproductive System

In human males, the primordial germ cells divide mitotically and produce spermatogonia. Some of the spermatogonia grow into large primary spermatocytes. Each primary spermatocyte undergoes first maturation division which is a reductional (meiotic) one. Thus, the primary spermatocyte divides into two haploid daughter cells called secondary spermatocytes. Each secondary spermatocyte now undergoes second maturation division which is a mitotic one. Thus, each secondary spermatocyte gives rise to two spermatids that undergo transformation to form two sperms. Overall, two secondary spermatocytes give rise to four sperms.

The correct option (D): Small part of the fallopian tube is removed or tied up.

The correct option (D): Urethra.