The graph below shows the position of a car (in miles from Gackle, ND) as a function of time (in minutes).

Find the slope of the line between the points $(57, 63.8)$ and $(104, 106.8)$. Include units in your answer.
Slope = .

Here is a list of units that WeBWorK understands.

What does the slope represent?
average velocity. The average velocity of the car on the interval $[57,104]$
speed. The speed of the car at time $t=57$
distance. The distance that the car travels between time $t=57$ and time $t=104$
grade. The grade of the road between mile $63.8$ and mile $106.8$
None of these. None of these