Answer : The motion of the object is, non-uniform
Explanation :
Uniform motion : It is defined as the movement of an object along a straight line with constant speed. It travels equal distances in equal time interval.
The average speed of an object is similar to the actual speed of an object. The distance-time graph shows a straight line.
Non-uniform motion : It is defined as the movement of an object along a straight line with variable speed. It travels unequal distances in equal time interval.
The average speed of an object is different to the actual speed of an object. The distance-time graph shows a curved line.
The given graph B is a non-uniform motion graph.
Hence, the motion of the object is, non-uniform