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.
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
选A。但我不理解OG给的解释: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 ....因为是filing of a deed使setting free变得可能,所以一定要用分词短语跟动名词。有这种说法吗?我也觉得这里应该用分词短语,但说不上为什么,只是朦胧的感觉。有谁能说说这里为什么一定要用分词短语吗?