大全377 ，一个很弱的问题

我想我已经是学傻了，问一个很弱的问题：

1.        In England the well-dressed gentleman of the eighteenth century protected their clothing while having their wig powdered by poking their head through a device that resembled the stocks.>>

(A) gentleman of the eighteenth century protected their clothing while having their wig powdered by poking their head>>

(B) gentleman of the eighteenth century protected his clothing while having his wig powdered by poking his head>>

(C) gentleman of the eighteenth century protected their clothing while having their wigs powdered by poking their heads>>

(D) gentlemen of the eighteenth century protected his clothing while having his wig powdered by poking his head（B）>>

(E) gentlemen of the eighteenth century protected their clothing while having his wig powdered by poking his head

by poking his head，这个POKING 是谁发出的动作？