A person travels a cenain distance at $$4\frac{1}{6}$$ m/sec and returns to the straight point at 12 km/h. His average speed (in km/h) is:

A

$$12\frac{1}{2}$$

B

$$13\frac{1}{3}$$

C

$$13\frac{1}{2}$$

D

$$10\frac{1}{3}$$