Egg is liberated from ovary in:

Explanation

The correct answer is: a. Secondary oocyte stage Now, let's explain all the options along with the reasons: a. Secondary oocyte stage: The secondary oocyte is the stage at which the egg is released from the ovary during ovulation. During ovulation, the mature ovarian follicle ruptures, and the secondary oocyte is expelled into the fallopian tube. It is in the secondary oocyte stage that the egg is liberated from the ovary. b. Primary oocyte stage: The primary oocyte is arrested in prophase I of meiosis and remains in this stage until it is selected for further development. It does not get released from the ovary. c. Oogonial stage: The oogonial stage is the earliest stage of oocyte development, where oogonia, which are precursor cells, undergo mitotic divisions to become primary oocytes. This stage occurs before the primary oocyte stage and well before ovulation. To summarize, the secondary oocyte stage is the correct answer because this is the stage at which the egg is released from the ovary during ovulation. The primary oocyte is arrested in prophase I, the oogonial stage is an earlier developmental stage, and "All of these" is not accurate as they represent different stages in oocyte development.