请教一道SC题目呀

bni

请问下面这一道题为什么D选项是错的？which修饰bond有问题吗？谢谢解答！

Declining values for bonds, the financial vehicles against which investors hedge to get through the bear market, is going to force currency trading to increase.

• A
  
  the financial vehicles against which investors hedge to get through the bear market, is
  
  
  
• B
  
  which investors use as financial vehicles to hedge against to get through the bear market, is
  
  
  
• C
  
  the financial vehicle which is hedged against by investors to get through the bear market is
  
  
  
• D
  
  which investors use as financial vehicles to hedge against to get through the bear market, are
  
  
  
• E
  
  the financial vehicles against which investors hedge to get through the bear market, are
  
  
  

贰乙〇

D：逗号which修饰的是他前面的NOUN / NOUN+modifier。D中which修饰bonds错误，语义就变成了投资者用bonds作为financial vehicles。
应该是用the financial vehicles 指代前面declining the values for bonds

bni

Among the reasons for the decline of New England agriculture in the last three decades were the high cost of land，the pressure of housing and commercial development，and basing a marketing and distribution system on importing produce from Florida and California.


D、a marketing and distribution system based on importing produce from Florida and California
E、a marketing and distribution system importing produce from Florida and California

E选项没有based on 为什么错了？