The graph below shows Lisa's distance from her home (y), in miles, after a certain amount of time (x), in minutes: Graph titled Lisas Distance Vs Time shows 0 to 10 on x and y axes at increments of 1. The label on x axis is time in minutes and that on y axis is Distance from Home in miles. Lines are joined at the ordered pairs 0, 0 and 1, 0.5 and 1.5, 1 and 2, 2 and 3, 2 and 4, 2 and 5, 3 and 6, 4 and 7, 5 and 8, 6.

Four students described Lisa's motion, as shown in the table below:

Student Description
Greg She drives at a variable speed for 2 minutes, then stops at a crossing for 2 minutes, and finally drives at a constant speed for the next 4 minutes.
Sam She drives at a variable speed for 2 minutes, then stops at a crossing for 4 minutes, and finally drives at a constant speed for the next 8 minutes.
Jane She drives at a variable speed for 2 minutes, then drives at a constant speed for the next 2 minutes, and finally drives at a variable speed for the next 4 minutes.
Pam She drives at a variable speed for 2 minutes, then drives at a constant speed for 4 minutes, and finally drives at a variable speed for the next 8 minutes.

Which student most accurately described Lisa's motion?
Greg
Sam
Jane
Pam