# If $x \frac{dy}{dx} = y (\log y - \log x + 1)$, then the solution of the equation is :
( A ) $\log (\frac{y}{x}) = cx$
( B ) $x \log (\frac{y}{x}) = cy$
( C ) $\log (\frac{x}{y}) = cy$
( D ) $y \log (\frac{x}{y}) = cx$