This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Gynaecology & Obstetrics
[{'content': 'Irregular and infrequent menstruation is known as: \nSelect and explain. \nA. Amenorrhoea, B. Oligomenorrhoea, C. Polymenorrhoea, D. Menorrhagia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Oligomenorrhoea - Infrequent and irregularly timed episodes of bleeding usually occuring at intervals of more than 35 days Polymenorrhoea - Frequent episodes of mentruation usually occurring at intervals of 21 days or less Menorrhagia - Increased menstrual flow/Increased duration at regular cycles Hypomenorrhoea - Scanty bleeding and shoer days of bleeding Metrorrhagia - Irregular bleeding in between the cycles Menometrorrhagia - Increased menstrual flow as well as irregular bleeding between the cycles', 'role': 'assistant'}]