For the reaction $A + B \rightarrow$ product,the rate of reaction is $3.6 \times 10^{-2} \ mol \ dm^{-3} \ sec^{-1}$. When $[A] = 0.2 \ mol \ dm^{-3}$ and $[B] = 0.1 \ mol \ dm^{-3}$,find the rate constant of the reaction if it is second order with respect to both reactants.

• A
  $18 \ mol^{-3} \ dm^9 \ sec^{-1}$
• B
  $90 \ mol^{-3} \ dm^9 \ sec^{-1}$
• C
  $72 \ mol^{-3} \ dm^9 \ sec^{-1}$
• D
  $36 \ mol^{-3} \ dm^9 \ sec^{-1}$