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
A patient presented at 20 weeks of gestation. The patient's LMP was 9th January. What will be the estimated date of delivery? 
Select and explain. 
A. 9th January, B. 16th September, C. 16th October, D. 9th October
C: 16th October
Answer: C: 16th October 
Explanation: Ans. is c, i.e. 16th OctoberEDD can be calculated by Naegele's formulaEDD=LMP+9 months and 7 daysSo to January add 9 months = OctoberTo 9 add 7=16Hence LMP of the female becomes- 16th October