This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Physiological changes during Pregnancy, Subject name: Gynaecology & Obstetrics
[{'content': 'An expectant mother feels quickening at: \nSelect and explain. \nA. 12-18 weeks, B. 16-20 weeks, C. 26 weeks, D. 24-28 weeks', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is b, i.e. 16-20 weeksRef. Dutta Obs 9/e, p 63: Reddy 27/e, p 434"Quickening (feeling of life) denotes the perception of active fetal movements by the women. It is usually felt about the 18th week Q, 2 weeks earlier in multiparae. Its appearance is a useful guide to calculate the expected date of delivery with reasonable accuracy" Ref. Dutta Obs, 9/e, p 63"Quickening is felt between 16th to 20th week Q" --Reddy 27/e, p 343PhenomenonTimePalpation of fetal part20 weeksActive fetal movement felt by placing a hand on abdomen20 weeksExternal ballottement20 weeksInternal ballottement16-28 weeksFHS audible by Stethoscope18-20 weeksFetal movement can be detected by Doppler10 weeksLightening38 weeks', 'role': 'assistant'}]