The correct option is B Metamorphosis of spermatids into sperms
Spermatogenesis is the process of sperm cell development. Rounded immature sperm cells undergo successive mitotic and meiotic divisions (spermatocytogenesis) and a metamorphic change (spermiogenesis) to produce spermatozoa.
So, spermiogenesis is the process by which haploid round spermatids complete series of events to become a spermatozoa.
Therefore, the correct answer is option 'b'.