Analysis of test questions: The material information shows that the amount of RMB exchange 100 on May 4th, 20 13 decreased compared with that on August 24th, 20 12, indicating that the exchange rate of the US dollar declined, the exchange rate of the US dollar depreciated against the RMB, the exchange rate of the RMB rose and the RMB appreciated against the US dollar. So b meets the meaning of the question; There is an error in ACD judgment. The answer to this question is B.