Carefully Examine the Following Reaction Sequence for the Catalytic Formation

Carefully examine the following reaction sequence for the catalytic formation of ozone, O₃, from molecular oxygen, O₂. Which chemical compound is behaving as the catalyst? O₂ + 2 NO → 2 N O₂
2 N O₂ → 2 NO + 2 O
2 O + 2 O₂ → 2 O₃

A) Nitrogen monoxide, NO
B) Nitrogen dioxide, N O₂
C) Oxygen, O₂
D) Atomic oxygen, O