The graph of an Identity function is?
For uniform motion :
(a) the distance-graph is a straight line parallel to the time axis.
(b) the speed-time graph is a straight line inclined to the time axis.
(c) the speed-time graph is a straight line parallel to the time axis.
(d) the acceleration-time graph is a straight line parallel to the time axis.
The graph of --------------- is a straight line parallel to y axis.