A car started at 9:00 a.m. from city A and stopped in city C at 10:00 a.m.. The diagram below shows the distance the car had traveled at different times.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1662006/original_1.JPG)
Which of the following graph represents the proportional relationship between the distance the car has traveled and time taken by it? What will be the average speed of the car?
[Hint: Average speed of the car = Slope of the distance-time graph]