During menstrual cycle, luteinizing hormone (LH) is secreted due to:

Explanation

This is the option marked correct in the official UHS answer key. The physiology worth carrying into the exam is that the LH surge is driven by rising oestrogen from the ripening follicle, which flips the pituitary from negative to positive feedback, and that FSH does fall in the mid follicular phase as inhibin from the growing follicle suppresses it. So the fall in FSH accompanies the surge rather than causing it, and no option here states the oestrogen rise directly.