This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Reproductive physiology and hormones in females, Subject name: Gynaecology & Obstetrics
Peak level of plasma progesterone in the luteal phase: 
Select and explain. 
A. 5 ng/ml, B. 10 ng/ml, C. 15 ng/ml, D. 30 ng/ml
C: 15 ng/ml
Answer: C: 15 ng/ml 
Explanation: Progesterone production and blood level Follicular phase luteal phase Production 2-3 mg 20-30 mg Serum value <1 ng/ml 5-15 ng/ml Ref: D.C. Dutta's Textbook of Gynaecology, 6th edition, page no: 75