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 fetomaternal transfusion of more than 30 ml has been found in what percentage of women at delivery: 
Select and explain. 
A. Less than 1%, B. 5%, C. 10%, D. 15%
C: 10%
Answer: C: 10% 
Explanation: 10%