This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of menstruation, Subject name: Gynaecology & Obstetrics
[{'content': 'A 30-year-old woman para 2, hypeension have menorrhagia. Which is best treatment for her? \nSelect and explain. \nA. Combined pills, B. Mirena, C. Hysterectomy, D. Transcervical resection of endometrium', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Mirena: It is employed to control menorrhagia It has no action on ovaries therefore E2 and progesterone levels remain normal Reduces blood loss by 70%-90% in 3months Can be retained for 5yrs Ref: Shaw Gynecology 17 e pg 136.', 'role': 'assistant'}]