Suman travels from place X to Y and Rekha travels from Y to X, simultaneously. After meeting on the way, Suman and Rekha reach Yand X, in 3 hours 12 minutes and one hour 48 minutes, respectively. If the speed of Rekha is 9 km/h, then the speed (in km/h) of Suman is:

A

$$7\frac{1}{2}$$

B

8

C

6

D

$$6\frac{3}{4}$$