During spermatogenesis, how many spermatids are produced for every primary spermatocyte that enters meiosis?

Four

Explanation:

During spermatogenesis, some diploid spermatogonia become larger in size and transform into primary spermatocytes. These diploid primary spermatocytes enter meiosis to produce haploid spermatids. One primary spermatocyte enters meiosis-I and produces two secondary spermatocytes. These secondary spermatocytes are haploids. Each of these two secondary spermatocytes enters the meiosis-II and produces two haploid spermatids. In this way, one diploid primary spermatocyte produces four haploid spermatids.