The knowledge points to be examined in analyzing this question are the basic principles and methods of stock index futures arbitrage. At present, there are four kinds of index futures of Chinese concept stocks listed, namely, China stock index futures of Chicago Board Options Exchange, hang seng china enterprises index futures contracts of Hong Kong, FTSE China 50 index futures of Xinhua Singapore and Shanghai-Shenzhen 300 index futures of China. These indexes all have the concept of China, and it is feasible to carry out cross-species spread arbitrage under the conditions of policies and so on. So the answer to this question is ACD.