This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pediatrics
Delayed puberty is when primary amenorrhea is seen without development of secondary sexual characters beyond the age of? 
Select and explain. 
A. 12 years, B. 14 years, C. 16 years, D. 18 years
C: 16 years
Answer: C: 16 years 
Explanation: c. 16 years(Ref: Nelson's 20/e p 2673, Ghai 8/e p 534)Delayed puberty is defined as absence of secondary sexual characters by 14 yrs age or absence of menarche by 16 years.