Obviously d futures. Treasury bonds are risk-free. Corporate bonds are a bit risky. The risk of stocks is relatively high, and futures are leveraged transactions, which are more than 10 times the risk of stocks.

To give a simple example, the margin ratio is 5%, and the corresponding leverage ratio is 20 times, which means that if the underlying asset rises or falls by 5%, you will either make a profit or lose everything. Do you think the risk is high?