This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Obstetrics, Subject name: Gynaecology & Obstetrics
Lochia, in its various forms, may normally persist for what time interval postpaum? 
Select and explain. 
A. 2 weeks, B. 4 weeks, C. 6 weeks, D. 8 weeks
B: 4 weeks
Answer: B: 4 weeks 
Explanation: - Sloughing of decidual tissue results in a vaginal discharge of variable quantity. For the first few days after delivery, there is blood sufficient to color it red--lochia rubra. - After 3 or 4 days, lochia becomes progressively pale in color--lochia serosa. After approximately the 10th day, because of an admixture of leukocytes and reduced fluid content, lochia assumes a white or yellow-white color--lochia alba. - The average duration of lochial discharge ranges from 24 to 36 days