I dont know y i can get this simple question

[success1111]

I am baffled that i dont seem to get this question right

(0.8)^-5/(0.4)^-4

(A) 3/32
(B) 5/64
(C) ½
(D) 1
(E) 2

[m&m]

is the answer B?

(0.8)^-5
-----------
(0.4)^-4

(0.4)^4
-----------
(2*0.4)^5

(0.4)^4
-----------
32*0.4^5

1
-----------
32*0.4

5
-----------
64

[success1111]

is the answer B?

(0.8)^-5
-----------
(0.4)^-4

(0.4)^4
-----------
(2*0.4)^5

(0.4)^4
-----------
32*0.4^5

1
-----------
32*0.4

5
-----------
64

incredible. OA is B. I really dont know how to handle my silly mistakes.
Thanks.