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 599 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
我想问的是画线部分前面的逗号，在判断setting是修饰主句主语的时候是否也有作用。 | 
