In case of a, the position will be lowered. Specific explanation: first of all, the operation of' short position closing' is buying, and the operation of' long position closing' is selling; Secondly, in the futures market, only positions will be reduced, and this market is a matchmaking transaction, that is, two positions must be closed by the counterparty (buy one and sell one) before trading can be carried out. Therefore, the operation descriptions of (b), (c) and (d) are all wrong and impossible. Only (a) is the correct description. By the way, you must have never done futures. This is just an exam. Well, I hope my answer can help you. Good luck! Don't forget to review for me, hehe! ! !