Answer: C

The basis refers to the difference between the spot price of a specific commodity at a specific time and place and the futures price of the commodity in the futures market, that is, the basis. = spot price - futures price. The basis can be positive or negative, depending on whether the spot price is higher or lower than the futures price. The basis contains two components, namely the two factors of "time" and "shortness" that separate the spot and futures markets. Therefore, the basis includes transportation costs and holding costs between the two markets. The former reflects the spatial factor between the spot and futures markets, which is the basic reason why the basis difference between two different locations is different at the same time; the latter reflects the time factor between the two markets, that is, two different delivery Monthly holding costs include storage fees, interest, insurance premiums, loss fees, etc. Among them, changes in interest rates have a great impact on the cost of ownership.