The correct option is C 60
As the species is diploid and the total number of chromosomes in primary spermatocyte = 60 ( primary spermatocyte is diploid in nature).
When the first round of meiosis will occur (i.e., meiosis I), the chromosomes will get reduced to half so subsequently the cells producing further will be haploid, the number of chromosomes they will contain is 30. Before meiosis I, the chromosomal DNA is replicated and each chromosome pair consists of four strands of DNA called chromatids. At the end of the first meiotic division, each secondary spermatocyte contains 30 chromosomes. Each of these chromosomes consists of paired chromatids. So for 30 chromosomes, the total number of chromatids will be 60.