Give the form of a particular solution of the differential equation y'' - 9y' - 20y = -3cos(4x) - 4e⁻^5x.

a) yₚ = Acos(4x) + Be⁻⁵x
b) yₚ = Asin(4x) + Be⁵^x
c) yₚ = Acos(4x) + Be⁵x
d) yₚ = Asin(4x) + Be⁻5x