问题详情

______ , the mayor conceded defeat in his bid for re-election.
A．Having racked up a lead of some 150000 votes
B．Having been racked up a lead of some 150000 votes
C．His opponent having racked up a lead of some 150000 votes
D．His opponent racking up a lead of some 150000 votes请帮忙给出正确答案和分析，谢谢！