Sound waves can be ranked by their intensity, I, given in this formula, where r is the distance from the source of a sound with a power output of P.

[tex]P = 4xr^{2} .[/tex]

Which equation correctly rewrites the formula to solve for I?

A. [tex]I = \frac{P}{4xr^{2} }[/tex]
B. [tex]I = \frac{Pxr^{2} }{4}[/tex]
C. [tex]I = 4Pxr^{2}[/tex]
D. [tex]I = \frac{4P}{xr^{2} }[/tex]