Which of the following is correct with respect to the graph given?
$\begin{aligned} & [R]=\text{Concentration at time } t \\ & [R]_0=\text{Initial concentration} \end{aligned}$

• A
  $I$ and $II$ represent zero order reaction.
• B
  $I$ represents first order and $II$ represents zero order reaction.
• C
  $I$ represents zero order and $II$ represents first order reaction.
• D
  $I$ and $II$ represent first order reaction.