The correct option is A ovulation
Ovulation is the release of ovum from one of the ovaries of a female. After the ovum/egg is released, it travels down the fallopian tube, where fertilisation by a sperm cell may occur.
Menstruation is a periodic discharge of blood, internal lining of the uterus and tissue debris from vagina.
Oogenesis is the process of production and development of the female gamete also called ovum.