In vertebrate animals,spermatogenesis and oogenesis differ in that

A)oogenesis begins at the onset of sexual maturity, whereas spermatogenesis begins during embryonic development.
B)oogenesis produces four haploid cells, whereas spermatogenesis produces only one functional spermatozoon.
C)cytokinesis is unequal in oogenesis, whereas it is equal in spermatogenesis.
D)oogenesis ends at menopause, whereas spermatogenesis is finished before birth.
E)spermatogenesis is not completed until after fertilization occurs, but oogenesis is completed by the time a girl is born.