Choosing ABC, the spot net price actually looks at the current market value of the deliverable bond target (the deliverable bond target in treasury bond futures is not single), and the conversion coefficient is actually the conversion rate of the deliverable bond target into the standard bond stipulated in the futures contract. In fact, the holding income should take into account the market yield of the relevant national debt, and the value of the delivery option is wrong at first glance. Treasury bond futures only accept physical delivery. The so-called physical delivery refers to bonds, not options.