A certain reaction occurs in two steps as:



(i) $2\text{S}{\text{O}}_2\left(\text{g}\right)+2\text{N}{\text{O}}_2\left(\text{g}\right)\to 2\text{S}{\text{O}}_3\left(\text{g}\right)+2\text{N}{\text{O}}_{}\left(\text{g}\right)$



(ii) $2\text{N}{\text{O}}_{}\left(\text{g}\right)+{\text{O}}_2\left(\text{g}\right)\to 2\text{N}{\text{O}}_2\left(\text{g}\right)$



In the reaction,

• A

  $\text{N}{\text{O}}_2\left(\text{g}\right)$ is intermediate
• Correct answer
  B

  $\text{N}{\text{O}}_{}\left(\text{g}\right)$ is intermediate
• C

  $\text{N}{\text{O}}_{}\left(\text{g}\right)$ is catalyst
• D

  ${\text{O}}_2\left(\text{g}\right)$ is intermediate

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