The correct option is A Secondary spermatocyte
During meiosis-I, primary spermatocyte is the main germ cell. It is diploid, (2n) with 44 + XY (total 46) chromosomes. It completes the first meiotic division (reduction division) leading to the formation of two equal, haploid cells called secondary spermatocytes, which have only 23 chromosomes each i.e. 22 + X or 22+ Y. So, at the end of first meiotic division, male germ cell differentiates into secondary spermatocyte.