为什么这里：鸟可以和土地比较？

fmsunny

Like the grassy fields and old pastures that the upland sandpiper needs for feeding and
nesting when it returns in May after wintering in the Argentine Pampas, the sandpipers
vanishing in the northeastern United States is a result of residential and industrial
development and of changes in farming practices.
A. the sandpipers vanishing in the northeastern United States is a result of residential and
industrial development and of changes in
B. the bird itself is vanishing in the northeastern United States as a result of residential and
industrial development and of changes in
C. that the birds themselves are vanishing in the northeastern United States is due to
residential and industrial development and changes to
D. in the northeastern United States, sandpipers’ vanishing is due to residential and industrial
development and to changes in
E. in the northeastern United States, the sandpipers’ vanishing, a result of residential and
industrial development and changing   答案 B

fmsunny

比较不是要求要对比一致吗？。。。其实按照最优原则我知道B答案比其他要好，但是我想知道为什么可以这样比？谢谢大家