Futures exchanges can adjust according to market risks, and the adjustment of price limit boards generally has the following characteristics: First. For newly listed varieties and newly listed futures contracts, the price limit is generally two to three times the price limit stipulated in the contract. Second, in the process of futures contract trading, when the contract price rises and falls in the same direction continuously, and there is a national legal holiday, or the exchange thinks that the market risk has changed obviously, the exchange can adjust the range of its price limit according to the market risk. Third. If more than two kinds of price limit boards specified by the exchange are adopted at the same time, the price limit board shall be determined according to the highest value of the specified price limit boards. So the answer to this question is BCD.