What is the order of the numbers from least to greatest? a = 1.5 x 10^3; b = 1.4 x 10^-1; c = 2 x 10^3; d = 1.4 x 10^-2 a: d < b < a < c* b: c < a < b < d c: d < a < c < b d: b < c < a < d