This is Kinematics and the equations in your book.
A speed time graph would plot the speed of something against the teime it was at a speed.
If it were changing it speed constantly, that would be a straight line if acclerating. Total distrance would be the area under the graph.
I think the answer may be the letter B
Sorry Man If you ask this question no one wants to write an essay and waste their time. You are smart enough to write an essay.