high low asymmetrical wears

A 21-year-old woman comes to the physician because of painful menstrual periods. Menarche was at age 13. During her first several cycles, her cramping was bearable, but since then it has grown increasingly worse. Her episodes are now characterized by lower abdominal pain that starts several hours prior to the onset of menses, lasts about 2 days, and then resolves completely. She has diarrhea and fatigue during this time. A year ago, a physician had her try ibuprofen, which helped significantly. Physical examination is unremarkable, and pelvic examination is normal. This patient's painful menstrual periods are related to which of the following substances? high low asymmetrical wears
(A) Endotoxin
(B) Nonsteroidal anti-inflammatory drugs (NSAIDs)
(C) Prolactin
(D) Prostaglandins
(E) Thyroid stimulating hormone (TSH)