Which of the following hormone levels will cause release of ovum...

The elevated estrogen levels act as a positive feedback mechanism by stimulating the anterior lobe of the pituitary to secrete luteinizing (LH) hormone, which initiates the next stage of the menstrual cycle. Rapid secretion of LH leading to its maximum level during the mid-cycle called LH surge induces the rupture of Graafian follicle and thereby the release of an ovum (ovulation).