For an object that is speeding up in the positive direction, what does the displacement vs. time graph look like?

displacement vs time graph will look like a parabolic shaped graph

Explanation:

As we know that the displacement of an object is given by kinematics equation when object is moving with uniform acceleration

So we know that

now here since velocity is increasing in positive X direction as well as the acceleration is also in same direction then the displacement vs time graph must be a straight line graph

so we will have

a is the best answer your welcome