In 2008, a school’s enrollment was 400 students. In 2012, the school’s enrollment was 640 students. Which linear model represents the school’s enrollment, s, as a function of t, the number of years after 2005? A. s(t)=60t+220
B. s(t)=220t+60
C. s(t)=4t+240
D. s(t)=240t+4
E. s(t)=60t
F. s(t)=240t