The correct option is B Diploid
The process of formation of a mature female gamete is known as oogenesis. It begins in embryonic stage when couple of million gamete mother cells(oogonia) are formed within the ovary. These cells start division and enter into prophase-I of the meiotic division, now known as primary oocytes. Now since the meiotic division isn't complete yet, the primary oocyte is diploid, i.e has 23 pairs of chromosomes. So the correct answer is B. The further division of the primary oocyte continues at puberty.