Which of the Following Statements About the Propagation Steps in the Chlorination

Which of the following statements about the propagation steps in the chlorination of ethane is true?

A) The second of the propagation steps is rate-determining because its transition state is at higher energy.
B) The first of the propagation steps is rate-determining because its transition state is at lower energy.
C) Radical chlorination consists of two propagation steps.
D) The energy diagram for the propagation steps has three energy barriers.