Answer: The rate determining step of this reaction would be step 2 and the best option to answer the question is the fourth one (letter D).
Step-by-step explanation:
The question requires us to identify the rate determining step in a reaction that happens in three steps, given that steps 1 and 3 are fast, and step 2 is slow.
The rate determining step of a reaction can be compared to the neck of a funnel where water needs to flow through: the rate by which water flows will be limited by the size of the neck of the funnel (because that is the available space for water flow) . In that sense, we can say that the rate of a chemical reaction is determined by its slow step.
Therefore, considering the three steps provided by the question (step 1 - fast, step 2 - slow, step 3 - fast), the rate determining step of this reaction would be step 2 and the best option to answer the question is the fourth one (letter D).