In a multi-step mechanism, which statement best explains why the overall rate may be controlled by steps other than the stoichiometry of the overall reaction?

• A. The rate is governed by the slowest elementary step (rate-determining step) and steady-state behavior of intermediates.
• B. The rate law is always determined by the first step.
• C. The rate is independent of intermediates.
• D. The rate is determined by the fastest step.

Answer: (A)