This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ectopic Pregnancy (Hello ! Where are you ?), Subject name: Gynaecology & Obstetrics
[{'content': 'Gestational sac can be seen earliest on transvaginal scan at \nSelect and explain. \nA. 4- 5 wks, B. 5 - 6 wks, C. 7 - 8 wks, D. 10 wks', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Gestational sac Cardiac activity Transvaginal sonography 4 + weeks 5 + weeks Transabdominal sonography 5 +weeks 6 + weeks Please note: in exams the same information may be asked as \'Which week gestational sac is seen" ? the answer choice maybe given as 5th week. so please realize that \'4 wks + some days\' is actually the 5th week.', 'role': 'assistant'}]