Chapter 11, Problem 90RPP

The threshold for pressure variation of a barely audible sound is about $\text{2 }\times {\text{ 10}}^{\text{-5}}{\text{N/m}}^{\text{2}}$. Which answer below is closest to the pressure variation of a barely audible sound in the cochlea of the inner ear?

$\begin{array}{l}\text{a}\text{. 1 }\times {\text{ 10}}^{\text{-7}}{\text{N/m}}^{\text{2}}\hfill \\ \text{b}\text{. 1 }\times {\text{ 10}}^{\text{-6}}{\text{N/m}}^{\text{2}}\hfill \\ \text{c}\text{. 2 }\times {\text{ 10}}^{\text{-5}}{\text{N/m}}^{\text{2}}\hfill \\ \text{d}\text{. 4 }\times {\text{ 10}}^{\text{-3}}{\text{N/m}}^{\text{2}}\hfill \\ \text{e}\text{. 4 }\times {\text{ 10}}^{\text{-2}}{\text{N/m}}^{\text{2}}\hfill \end{array}$