154. In 1791 Robert Carter III, one of the wealthiest plantation owners in Virginia, stunned his family, friends, and neighbors by filing a deed of emancipation, setting free the more than 500 slaves who were legally considered his property.

(A) setting free the more than 500 slaves who were legally considered

(B) setting free more than the 500 slaves legally considered as

(C) and set free more than 500 slaves, who were legally considered as

(D) and set free more than the 500 slaves who were legally considered

(E) and he set free the more than 500 slaves who were legally considered as

This sentence requires that the participial phrase setting free... connect to the gerund construction by filing a deed...; it was the filing of a deed that made possible the setting free.... Choices A and B establish this connection, but only A, the best choice, completes the participial phrase appropriately. In choices B and D the misconstructed phrases set[ting] free more than the 500 slaves... mistakenly suggest that Carter set free slaves that were not his own. Choices C and D distort meaning by paralleling stunned and set free, as though these were two separate and independent actions. E begins a second independent clause, which—though grammatically acceptable—again distorts the meaning. In choices B, C, and E, considered as is unidiomatic.

在这里，逗号+setting free the more than 500 slaves who were legally considered his property.

作什么成分，是修饰stunned，作结果状语么？

如果是这样的话，则setting free…是stunned这个动作产生的结果，

可解释中说it was the filing of a deed that made possible the setting free....

怎么理解这句话，如果setting是修饰stunned这个动作的，为什么要说the filing of a deed made the setting free possible，难道setting free…与the filing of有关系么，或者说setting free是由the filing of决定的么？

请同学解答，谢谢；

it was the filing of a deed that made possible the setting free
应该是说 这个契约的签订使setting free成为可能，
‘setting free...’ 是解释说明  ’filing a deed of emancipation‘ 这个行为的

望大家指正。

个人的感觉这里 setting free短语做句子谓语动词stun的伴随状语，

也就是说 这哥么儿 通过放奴隶这种方式，震惊了 他的朋友家人和邻居

非常非常sorry，我没有看懂你的意思，你认为setting free是作结果状语修饰主句的动作(stunned)的么？还是作什么其他成分呢？

你所说的 这个契约的签订使setting free成为可能，是决定setting使用分词的原因是么？

按照OG的说法，setting...是结果状语修饰the filing...的。
如果说setting...是修饰stunned的，逻辑上不通啊。
至于为什么setting..不是用来修饰stunned的，我程度太浅说不来 。不过我觉得

setting...可以用来修饰the filing吧，不然应该怎样来表达这个意思呢？
供讨论

OG的原文应该是出自此

Two hundred years ago, Carter, one of the wealthiest men in Virginia who owned 60,000 acres on 18 plantations stunned his family, friends and neighbors by filing what was called a deed of emancipation, or manumission, setting free the more than 500 "negroes & mulatto slaves" who were his "absolute property."

sb stunned sb by +N,

setting free是adj角色修饰emancipation

一点想法！