To solve this problem, we need to determine when the meiotic division of the secondary oocyte is completed. Let's analyze the process of oocyte development:$\newline \bullet$The primary oocyte undergoes the first meiotic division to form a secondary oocyte and a polar body. This division is completed before ovulation.$\newline \bullet$The secondary oocyte is arrested in metaphase II of meiosis and is released during ovulation.$\newline \bullet$The completion of the second meiotic division occurs only if the secondary oocyte is fertilized by a sperm.$\newline \bullet$Upon fertilization, the secondary oocyte completes meiosis II, resulting in the formation of an ovum and a second polar body.$\newline$Therefore, the meiotic division of the secondary oocyte is completed at the time of fusion of a sperm with an ovum.$\newline$This corresponds to Option 3.