prep139 指代

On Earth, among the surest indications of sunspot cycles are believed to be the rate that trees grow,as seen in the rings visible in the cross sections of their trunks.

(A) On Earth, among the surest indications of sunspot cycles are believed to be the rate that trees grow

(B) On Earth, among the surest indications of sunspot cycles are, it is believed, the rate of tree growth

(C) On Earth, the rate at which trees grow is believed to be among the surest indications of sunspot cycles

(D) Among the surest indications on Earth of sunspot cycles, believed to be the tree growth rate

(E) Among the surest indications on Earth of sunspot cycles is believed to be the rate at which trees grow

※句子结构：Among… is believed to be…

倒装结构，主词是the rate，由which引导形容词子句修饰。
            

(C) on earth 放置句首修饰整个句子，不符合逻辑；their 的指代存在歧义，离它最近的是sunspot cycles，未划线部分的as seen 应该要紧跟其修饰的名词。

我的问题是：很奇怪，E选项正确， as seen 就近修饰什么呢？ trees grow 是动词啊？是修饰the rate 吗？那不也是跳跃指代吗？

还有， C中sunspot cycles 为什么不能成为as seen 修饰的对象呢？

哪位牛牛出来讲讲。谢谢！

Seen对象只能是indications, 我这么觉得。