This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Embryology 2, Subject name: Anatomy
In the production of female gametes, which of the following cells can remain dormant for 12-40 years 
Select and explain. 
A. Primordial germ cell, B. Primary oocyte, C. Secondary oocyte, D. First polar body
B: Primary oocyte
Answer: B: Primary oocyte 
Explanation: Primary oocytes are formed by month 5 of fetal life and remain dormant until pubey, when hormonal changes in the young woman stimulate the ovarian and menstrual cycles. From 5 to 15 oocytes will then begin maturation with each ovarian cycle throughout the woman's reproductive life.