Answer:
Here is an image attached with similar questions.
The correct answer is D where acceleration is function of time.
Explanation:
The force acting on the object is constant.
There is no change in the application of forces.
And we know that Force is the product of acceleration and masses.
Newtons second law: 
Regarding mass we know that it can neither be created nor destroyed.
So in
we have two constant terms, constant divided by constant will give the same result as 
There is no change in acceleration
with respect to time
.
So the most appropriate graph where time (t) is changing on
but acceleration doesn't changes is D.
The graph will be similar to
and will be horizontal to the
.
Option D depicts the same.