Which equations represent decreasing exponential functions? Select all that apply.

A. f(x) = 8(0.64)^0.5x
B. f(x) = 4(0.45)^x
C. f(x) = 0.75^x
D. f(x) = 5(1.2)^2x
E. f(x) = 0.5(0.9)^5x
F. f(x) = 2.5^3x

B. f(x) = 4(0.45)^x

E. f(x) = 0.5(0.9)^5x