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
Rule of Hasse is used to determine: 
Select and explain. 
A. The age of fetus, B. Height of an adult, C. Race of a person, D. Identification
A: The age of fetus
Answer: A: The age of fetus 
Explanation: None