Find the unit tangent vector at the point t=0 for the parametric curve r t = . OA. O B. 1 0, 2 OC. OD. Given the acceleration a(t) = , initial velocity v(0) = , and initial position (0) = find the position vector r(t) for any tz0. OAT ( t ) = O B. 3 P ( t ) = OCT ( t ) = OD. P ( t ) =