This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Obs), Subject name: Gynaecology & Obstetrics
[{'content': "Menorrhagia ('heavy periods') is defined as a blood loss of greater than: \nSelect and explain. \nA. 35 mL per period, B. 55 mL per period, C. 80 mL per period, D. 120 mL per period", 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. C. 80mL per period* Menorrhagia ('heavy periods') is defined as a blood loss of greater than 80 mL per period.* This definition is rather arbitrary but represents the level of blood loss at which a fall in hemoglobins and hematocrit concentration commonly occurs.", 'role': 'assistant'}]