The Distance Traveled by a Car in the X-Direction Is

Multiple Choice

The distance traveled by a car in the x-direction is shown.When the car changes speed for t = 10 s to 15 s,it does so uniformly.Use the graph below to answer the question.
-If the position of an object is plotted vertically on a graph and the time is plotted horizontally,the instantaneous velocity at a particular time is

A) the height of the curve at that time.
B) the total length of the curve.
C) the slope of the tangent to the curve at that time.
D) the area under the curve from zero to that time.
E) impossible to determine from this type of plot.