A 3-nC charge and a 1-nC charge are spaced a distance of 1 cm from each other. Because of this, the 1-nC charge feels a certain force. Now if instead we take the same two charges and place them at a distance of 2 cm from each other, the magnitude of the force felt by the 1-nC charge is

1. 1/3 of
2. 1/9 of
3. the same as
4. 1/2 of
5. 1/4 of

what it was originally.