Study the graph shown. It is a graphic of a car trip taken by Karen and her mother. The starting position (0,0) is their home. Graph of position versus time with position on y axis from 0 to 80 miles and time on x axis from 0 to 5 hours. Segment 1 goes from 0, 0 to 1, 40. Segment 2 goes from 1, 40 to 2, 40. Segment 3 goes from 2, 40 to 3, 60. Segment 4 goes from 3, 60 to 4, 75. Segment 5 goes from 4, 75 to 5, 75.

Identify the time period(s) during the trip when the car was traveling at the greatest average speed.