Use the following diagram for the next four questions. The particle models shown above represent a proposed two-step mechanism for the destruction of ozone (O3) in the upper atmosphere.
Based on the proposed mechanism, which of the following best describes the concentration of the species represented above as the reaction occurs?
A. The concentration is larger than that of reactant or product.
B. The concentration is very low for the duration of the reaction.
C. The concentration increases steadily as the reaction proceeds.
D. The concentration fluctuates between high and low during the reaction.