The local maximum value $l$ and local minimum value $m$ of $f(x)=\frac{x^2+2 x+2}{x+1}$ in $\mathbb{R}-\{-1\}$ exist at $\alpha, \beta$ respectively, then $\frac{l+m}{\alpha+\beta}=$

• Correct answer
  A

  $0$
• B

  $-4$
• C

  $-2$
• D

  $2$

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