Observe the following line diagram depicting the 28 days menstrual cycle of a healthy young woman.

Options :

1. Most fertile days : 14 - 21 , Least fertile days : 1 - 7

2. Most fertile days : 10 - 17 , Least fertile days : 21 - 28

3. Most fertile days : 1 - 7 , Least fertile days : 14 - 21

4. Most fertile days : 21 - 28 , Least fertile days : 7 - 14