Correct Answer: A
Explanation:
One immature primary spermatocyte which is diploid divides to produce two haploid secondary spermatocytes. Each of these then divides to produce four spermatids which are haploid. Each spermatid is converted by cytoplasmic elimination into as mature spermatozoon. Thus four haploid spermatozoa (i.e., mature sperm) are produced from one diploid primary spermatocyte entering meiosis.