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
Safe period in rhythms method is : (In a female with 28 days menstrual cycle) : 
Select and explain. 
A. Initial 14 days, B. Later 14 days, C. First and last 7 days, D. 10 to 21 days of the cycle
C: First and last 7 days
Answer: C: First and last 7 days 
Explanation: First and last 7 days