Many questions were asked，particularly the cost of the new plan.
A. in reply to
B. in relation to
C. in act to
D. in addition to
网友回答
A. in reply to
(答案→)B. in relation to
C. in act to
D. in addition to
解析：句意：很多问题，尤其是关于新计划的成本被问到了。in relation to“关于”，和题意相符。