The reaction of ozone with oxygen atoms in the presence of chlorine atoms can occur by a two-step process shown below:
$O_{3(g)} + Cl_{(g)}^{\bullet} \to O_{2(g)} + ClO_{(g)}^{\bullet}$ ..... $(i)$ $K_i = 5.2 \times 10^9 \ L \ mol^{-1} \ s^{-1}$
$ClO_{(g)}^{\bullet} + O_{(g)}^{\bullet} \to O_{2(g)} + Cl_{(g)}^{\bullet}$ ..... $(ii)$ $K_{ii} = 2.6 \times 10^{10} \ L \ mol^{-1} \ s^{-1}$
The closest rate constant for the overall reaction
$O_{3(g)} + O_{(g)}^{\bullet} \to 2O_{2(g)}$ is ........... $L \ mol^{-1} \ s^{-1}$

• A
  $1.4 \times 10^{20}$
• B
  $3.1 \times 10^{10}$
• C
  $5.2 \times 10^9$
• D
  $2.6 \times 10^{10}$