Which equation would best help solve the following problem?
Rennie kicks a field goal with an initial vertical velocity of 31 meters per second. How long will it take the football to hit the ground?
A. –4.9t^2 + 31t = 0
B. –4.9t^2 – 31t = 0
C. 16t^2 + 31t = 0
D. –16t^2+ 31t = 0