The reason why only the short seller of treasury bond options has the right to choose creditor's rights is because the short seller of treasury bond futures in China implements the system of raising hands. Because the short delivery of treasury bonds futures in China is implemented by raising hands, short sellers can choose any one of a series of treasury bonds similar to the underlying assets of the contract for delivery. The sellers of treasury bonds futures include conversion options, opportunity options and month-end options in the delivery process. Conversion option is the right that the short seller of treasury bond futures has to choose the final delivery certificate from a basket of deliverable certificates before delivery, that is, choose creditor's rights.