OG紫 16

16．Declining values for farm equipment and land，the collateral against which farmers borrow to through the harvest season, is going to force many lenders to tighten or deny credit this spring．

(A)the collateral against which farmers borrow to get through the harvest season，is
(B)which farmers use as collateral to borrow against to get through the harvest season，is
(C)the collateral which is borrowed against by farmers to get through the harvest season，is
(D)which farmers use as collateral to borrow against to get through the harvest season，are
(E)the collateral against which farmers borrow to get through the harvest season，are

The correct answer is E．

请问D为什么不对啊？
The collarteral 为什么不是 farm equipment and land的同位语？它不是直接解释了farm equipment and land吗? 为什么它是Declining values 的同位语？？谢谢