Analysis of test questions: RMB appreciation is negatively correlated with the decline of foreign exchange rate; When the price of a commodity rises, the producer's profit increases and the supply increases, which is in direct proportion to the meaning of the question; When the price of a commodity rises, people's demand for it decreases, which is inversely proportional to the relationship, consistent with the meaning of the question; Currency depreciation is inversely proportional to price increase, which is consistent with the meaning of the question; The amount of money needed in circulation is directly proportional to the price level of the goods for sale, and ④ it is inconsistent with the meaning of the question. Choose b for this topic.