What is the instantaneous acceleration at t=0? 0.6 m/s^2 1.67 m/s ^2 4.6 m/s ^2 6.27 m/s^2

Olympic skier tina maze skis down a steep slope that descends at an angle of 30∘ below the horizontal. the coefficient of sliding friction between her skis and the snow is 0.10. i found maze's acceleration which is 4.1 m/s^2. but how do you determine maze's speed 4.0 s after starting?