For a uniform motion,
A. the velocity – time graph is a straight line parallel to the time axis.
B. the position – time graph is a parabola.
C. The acceleration – time graph is a straight line inclined with time axis.
D. none of the above.

Hint: Objects in uniform motion travel equal displacements in equal time intervals. Objects in uniform motion do not speed up, slow down, or change direction. Now find out the graph which represents such a type of motion.

Complete step by step answer:
As we know that if a body covers equal distances in equal time intervals then it is said to move with uniform velocity and its motion is called uniform motion.
The velocity versus time (v – t) graph for a body moving with uniform speed is given as,


This graph represents that the body is in uniform motion because the velocity of the body remains constant and the body is covering equal distance in equal time interval of time.
This velocity vs. time (v – t) graph is a straight line parallel to the time (t) axis.
Hence, the correct option is A, i.e., the velocity – time graph is a straight line parallel to time axis.

Additional Information:
For representing uniform motion, if we plot a displacement (d) vs. time (t) graph then it will be a straight line inclined with time axis, which represents that the object covers equal distances in equal intervals of time.

Note: Students should understand the uniform motion and thereafter they need to know how to plot displacement vs. time graph and velocity vs. time graphs for representing the uniform motion. If the position vs. time graph is a parabola then it will represent non-uniform motion, so option B is incorrect and if the acceleration vs. time graph is a straight line inclined with time axis then it will represent increasing acceleration which is also a non-uniform motion, so option C is incorrect.