A boy standing in front of a wall produces two whistles per second. He notices that the sound of his whistling coincides with the echo. The eacho is heard only once when whistling is stopped. Calculate the distance between the boy and the wall. (The speed of soudn in air = 320 m/s)
The distance at which the boy is standing from the wall :

Options

A. 160 m
B. 240 m
C. 320 m
D. 80 m