A safety inspector is determining the intensity of a sound. Close to a loudspeaker, his meter shows an intensity $I$. This is associated with an amplitude $A$ for the sound wave. At a different position, the meter shows an intensity reading of $2I$. What amplitude does the sound wave have there?
- A$\frac{A}{\sqrt{2}}$
- B$\sqrt{2}A$
- C$2A$
- D$4A$