Correct choice is (a) Primary oocyte: Diploid; Secondary oocyte: Haploid; Ovum: Haploid
Explanation: The diploid oogonium goes through the first round of meiosis to form primary oocyte, which is arrested at Prophase I. Thus, the primary oocyte is also diploid. The division is completed after the formation of the secondary oocyte, which is haploid. The secondary oocyte undergoes another round of meiosis to form haploid ovum.