Which graph represents a state of rest for an object?

A bus is travelling the first one-third distance at a speed of 10 km/h, the next one-fourth at 20 km/h and the remaining at 40 km/h. What is the average speed of the bus?

A car A is travelling on a straight level road with a uniform speed of 60 km/h. It is followed by another car B. Which is moving with a speed of 70 km/h. When the distance between them is 2.5 km, the car B is given a deceleration of 20 km/h². After how much time will B catch up with A?

A sprinter has to cover a total run of 100 m. She increases her speed from rest under a uniform acceleration of 1.0 m/s² up to three quarters of the total run and covers the last quarter him uniform speed. The time she takes to cover the first half, and to cover the second half of the run will be

A bus begin to move with an acceleration of 1 m/s². A man who is 48 m behind the bus starts running at 10 m/s to catch the bus. The man will be able to catch the bus after.