This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
A patient had undergo suction evacuation for 10 weeks pregnancy. Three days later she came back with profuse vaginal bleeding and abdominal pain. The most likely diagnosis is : 
Select and explain. 
A. Uterine atony, B. Cervical injury, C. Retained products, D. Uterine perforation
C: Retained products
Answer: C: Retained products 
Explanation: Retained products