The solution of the differential equation

$\frac{d^2y}{dx^2}$ – $\frac{dy}{dx}$ + 0.25y = 0, given y = 0 at x = 0 and  $\frac{dy}{dx}$ = 1 at x = 0 is

1. xe$^{0.5x}$ – xe$^{-0.5x}$
2. 0.5xe$^{x}$ – 0.5xe$^{-x}$
3. xe$^{0.5x}$
4. -xe$^{0.5x}$