Which number is the smallest?

Responses
A 1.28 x
1.28 x 10 -4
B 2.85 x
2.85 x 10 -6
C 3.24 x
3.24 x 10 -5
D 4.68 x
4.68 x 10 -4
E 5.48 x

10-7

B 2.85 x
2.85 x 10 -6