This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sexuality and intersexuality, Subject name: Gynaecology & Obstetrics
Premature ovarian insufficiency is defined as hypogonadotropic hypogonadism and amenorrhea arising before the age of 
Select and explain. 
A. 40 years, B. 45 years, C. 50 years, D. 55 years
A: 40 years
Answer: A: 40 years 
Explanation: Premature ovarian failure (POF), traditionally defined as hypogonadotropic hypogonadism and amenorrhea arising before the age of 40.Reference: Clinical gynecologic endocrinology; 10th edition; Chapter 9; Normal and Abnormal Sexual Development; Page no: 463