This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Best method of assessing foetal well being at term is by serial estimation of : 
Select and explain. 
A. Oestriol, B. Pregnanidiol, C. HPL, D. All of the above
A: Oestriol
Answer: A: Oestriol 
Explanation: Oestriol