The formula that describes an object's motion is given by S=ut+1/2at^2 , where S is the distance traveled, u is the initial velocity, a is the acceleration , and t is the time.
Which equation represents a in terms of the other variables?
A. a= 2S-2u/t
B. a=2S+2u/t
C. a=2S-2ut/t^2
D. a=2S+2ut/t^2