The overall rate $\frac{\mathrm{d}\left[\mathrm{P}\right]}{\mathrm{d}\mathrm{t}}$, for the reaction $\text{2A}\stackrel{\text{K}}{\rightleftharpoons }\text{B;}\text{B}\text{+}\text{C}\stackrel{{\text{k}}_{\text{f}}}{\to }\text{P}$ is given by

• Correct answer
  A

  $\mathrm{K}{\mathrm{k}}_{\mathrm{f}}\left[\mathrm{A}{]}^2\right[\mathrm{C}]$
• B

  $\mathrm{K}\left[\mathrm{A}\right]\left[\mathrm{B}\right]$
• C

  ${\mathrm{k}}_{\mathrm{f}}\left[\mathrm{B}\right]\left[\mathrm{C}\right]$
• D

  $\mathrm{K}{\mathrm{k}}_{\mathrm{f}}\left[\mathrm{A}{]}^2\right[\mathrm{B}\left]\right[\mathrm{C}]$

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