A projectile is fired vertically upward and has a position given by s(t) = - 161- + 320t + 336 for 0 sts 21. Complete parts (a) (e) below. a. Graph the position function for 0 Ets 21. Choose the correct graph below. Each curve is graphed in a [ - 4,21, 1] by [0,3200, 100] window. OA. O B. VC. O D. b. From the graph of the position function, identify the time at which the projectile has an instantaneous velocity of zero; call this time t = a t= (Type an integer or a decimal.)