If $y=x \operatorname{Tan}^{-1}\left(\frac{x}{y}\right)$, then $\frac{d y}{d x}=$

• A

  $\frac{x y^2}{x^2+y^2}$
• B

  $\frac{x y}{x^2+y^2}$
• Correct answer
  C

  $\frac{y}{x}$
• D

  $\frac{y}{x(x+y)}$

Hence, the correct answer is option: 'C'.