A writer buys a new laptop for $1866. Every year the laptop decreases in value by 20% Which exponential function can be used to find the value of the laptop after u years? a. A(u) = 1866(1.8)ᵘ b. A(u) = 1866(0.8)ᵘ c. A(u) = 1866(0.2)ᵘ d. A(u) = 1866(1.2)ᵘ