Generally speaking, if ________ according to the instructions, the electric-bike is not so dangerous

Generally speaking, if ________ according to the instructions, the electric-bike is not so dangerous as reported．

A.riding

B.ridden

C.to ride

D.to be ridden

答案及解析： B

解析：

ride(骑)与主语the electric-bike属被动关系，所以要用过去分词ridden作状语。