Two girls move in opposite directions, one from A to B and the other from B to A. The girl from A reaches the destination in 12 minutes. The girl from B stops on the way for 10 minutes and reaches her destination in 25 minutes. If A's speed is 5 km/h, then what is the speed of B?

A

3 km/h

B

$$\frac{1}{7}$$ km/h

C

4 km/h

D

2.4 km/h