the given series is ,
90 , 906 , 9066 , 90666
common difference = d = 906 - 90 = 816
d = 9066 - 906 = 8160
as common difference is not same,
so it is not airthmatic series,
common ratio,
906/90 = 10.6
9066/906 = 10.006
90666/9066 = 10.0006
also, the common difference is not the same,
so also it is nota a geometric series,
thus, the answer is option A