影响需求价格弹性的因素有（）。

A.替代品的数量和相近程度

B.商品的重要性

C.商品用途的多少

D.资金有机构成不同

E.生产周期和自然条件

The table below summarizes the yields and corresponding price for a hypothetical 15 -year option-free bond that is initially priced to sell at 7% yield: Yield (%)Price ($) 6.90% 100.925 47.00 % 100.0000 7.10% 99.0861 Using a 10 basis point rate shock, the effective duration for this bond closest to:（）

A. 4.6 years.

B. 7.5 years.

C. 9.2 years.