The Figure Shows the Speed as a Function of Time

Multiple Choice

The figure shows the speed as a function of time for an object in free fall near the surface of the earth. The object was dropped from rest in a long evacuated cylinder.
-What is the numerical value of the slope of the line?

A) 1.0 m/s²
B) 2.0 m/s²
C) 7.7 m/s²
D) 9.8 m/s²
E) This cannot be determined from the information given since the speed and time values are unknown.