A line graph displays the distance traveled by a car over a duration of 5 hours. The distance is measured in miles and the time in hours. Here are the distance measurements:
At hour 1: 20 miles
At hour 2: 40 miles
At hour 3: 70 miles
At hour 4: 90 miles
At hour 5: 120 miles
Based on the graph, which of the following statements is true?