A student strikes his hands together while standing near a wall and hears the echoes return. He makes each clap at exactly the instant he hears the echo from the clap before it. A different student begins a stop-watch at the first clap and stops it at the eleventh clap. The stop-watch shows $9.4\ \text{\,s}$, and the speed of sound is $320\ \text{m s}^{-1}$. What is the distance $x$ between the student and the wall?
- A$140\ \text{m}$
- B$150\ \text{m}$
- C$270\ \text{m}$
- D$300\ \text{m}$