Sindhu can cover a distance of $$20 \frac{2}{3}$$ km in $$7 \frac{3}{4}$$ hours on foot. How many km per hour does she walk?

A

4 km

B

$$\frac{2}{3}$$ km

C

$$2\frac{2}{3}$$ km

D

$$3\frac{2}{3}$$ km