老师能解析下这道题目吗？

问题如下：

For a forward contract with a value of zero, a situation where the spot price is above the forward price is best explained by high:

选项：

A.interest rates.

B.storage costs.

C.convenience yield.

解释：

C is correct. If the convenience yield is high, holding the underlying confers large benefits, thus the spot price can exceed the forward price for a forward contract with a value of zero. Based on the formula V_t(T) = S_t –PV_T(I)+PV_T(C)– F₀(T)(1 + r)^–(T–t)and an initial value V_t(0) of zero, large benefits PV_T(I) explain why the spot price can exceed the forward price.

A is incorrect. High interest rates make the forward contract more valuable. Thus, the forward rate is above the spot rate.

B is incorrect. High storage costs make the forward contract more valuable. Thus, the forward rate is above the spot rate.