At which stage the primary oocytes get temporarily arrested?

At prophase -I of meiosis.

The correct answer is Option (2) -At prophase -I of meiosis.

During oogenesis (the process of egg cell development), the primary oocytes undergo meiosis, a type of cell division that reduces the chromosome number by half. The primary oocytes begin meiosis but get temporarily arrested at Prophase I. This arrest occurs during fetal development, and the primary oocytes remain in this state until a woman reaches puberty.

Upon reaching puberty, with each menstrual cycle, a certain number of primary oocytes are activated to resume meiosis. One primary oocyte completes meiosis I, resulting in the formation of a secondary oocyte and a polar body. The secondary oocyte then enters meiosis II but arrests at Metaphase II until fertilization occurs.

The temporary arrest at Prophase I ensures that the primary oocytes are maintained in a suspended state until they are needed for ovulation and potential fertilization. This process helps to ensure a continuous supply of mature eggs throughout a woman's reproductive years.