A school is located between two cliffs. When the metal bell is struck by school attendant, first echo is heard by him after $$2.4 s$$ and second echo follows after $$2.0 s$$ for him at the same position near the bell. If the velocity of sound in air is $$340 ms-1$$ at the temperature of the surroundings, then the distance between the cliffs is approximately____.

A

$$0.488\text{ km}$$

B

$$0.751\text{ km}$$

C

$$1.16\text{ km}$$

D

$$1.41\text{ km}$$