This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Normal Menstruation, Abnormal Menstruation, Menopausal Physiology and forsight of conception, Subject name: Gynaecology & Obstetrics
A 20 year old woman gives a history of sharp pain in the lower abdomen for 2-3 days every month approximately 2 weeks before the menses. The most probable etiology for her pain is: 
Select and explain. 
A. Endometriosis, B. Dysmenorrhea, C. Pelvic tuberculosis, D. Mittelschmerz
D: Mittelschmerz
Answer: D: Mittelschmerz 
Explanation: Midcycle pain or Ovulation pain is called Mittelschmerz . This is because of the blood, fluid and cellular debris which comes out of the ruptured ovarian follicle trickles to the pelvis and causes a mild peritoneal irritation and pain, often limited to that side of ovulation.