The function s = f(t) gives the position of a body moving on a coordinate line, with s in meters and t in seconds.
s = 3t + 3t + 8.0t^2. Find the body's displacement and average velocity for the given time interval.
Options:
A. 34m, 17m/sec
B. 18m, 18m/sec
C. 12m, 15m/sec
D. 18m, 9m/sec