A man is positioned $80\,\text{m}$ in front of a cliff face. He produces a loud bang and waits for the echo. He produces a loud bang every second. He hears an echo exactly halfway between the bang that produced it and the following bang. What is the speed of sound?
- A40 $\text{m s}^{-1}$
- B80 $\text{m s}^{-1}$
- C160 $\text{m s}^{-1}$
- D320 $\text{m s}^{-1}$