可以用图来解释一下这题吗？

问题如下：

All else being equal, the difference between the nominal spread and the Z-spread for a non-Treasury security will most likely be larger when the:

选项：

A.

yield curve is steep.

B.

yield curve is flat.

C.

security has a bullet maturity rather than an amortizing structure.

解释：

Correct Answer: A

The main factor causing any difference between the nominal spread and the Z-spread is the shape of the Treasury spot rate curve. The steeper the spot rate curve, the greater the difference.