A man fires a gun 150 m from a cliff. A second man who is standing 300 m further away from the cliff hears the gun 1 second after he sees the flash. The second man will hear the echo from the cliff
(A) 1 second after seeing the flash
(B) 2 seconds after hearing the gun
(C) 2 seconds after seeing the flash
(D) 4 seconds after hearing the gun.