What is one difference between oogenesis and spermatogenesis?

A-Oogenesis occurs in females, but spermatogenesis occurs in males.
B-Oogenesis starts at puberty, but spermatogenesis starts before birth.
C-Oogenesis involves mitosis, but spermatogenesis involves meiosis.
D-Oogenesis involves differentiation, but spermatogenesis does not involve any differentiation.