What can you say about the motion of a body if its displacement$-$time graph is a straight line parallel to the time axis?

What can you conclude about the motion of a body depicted by the velocity-time graphs $(i)$,$(ii)$ and $(iii)$ given below?

$(a)$ Which type of motion is represented by the velocity-time graph shown below?
$(b)$ Name the physical quantity which can be calculated by the area of rectangle $OABC$.
$(c)$ What does the straight line $AB$ represent?

The diagram shows a velocity-time graph for a car starting from rest. The graph has three sections $AB$,$BC$,and $CD$.
$(i)$ From a study of this graph,state how the distance travelled in any section is determined.
$(ii)$ Compare the distance travelled in section $BC$ with the distance travelled in section $AB$.
$(iii)$ In which section does the car have zero acceleration?
$(iv)$ Is the magnitude of acceleration higher or lower than that of retardation? Give a reason.

What type of motion is represented by the following graphs?

What can you say about the motion of an object if its speed-time graph is a straight line parallel to the time axis?