A 16-year-old presents to the clinic with a history of heavy and prolonged menstrual bleeding since her menarche at 13 years of age. Her cycles have been regular for the last year, but they have always been heavy. Her family history is relevant for heavy menstrual bleeding in both her mother and sister. The most likely explanation for her menorrhagia is: Group of answer choices Von Willebrand disease Ovulatory dysfunction Hypothyroidism Immature hypothalamic pituitary ovarian axis