He asked his father______.A.where it happens B.where it was happend C.how it happend D.how it happen

He asked his father______.A.where it happens B.where it was happend C.how it happend D.how it happen
He asked his father______.
A.where it happens
B.where it was happend
C.how it happend
D.how it happen

He asked his father______.A.where it happens B.where it was happend C.how it happend D.how it happen
C ( 主句是一般过去时asked ,从句要用相应的过去时,排除A与D,HAPPEN 是不及物动词,没有被动词语态,再排除B）

B
was与主句的时态要一致

c