Final answer:
The slope of a velocity vs. time graph represents acceleration, which is the rate of change of velocity with respect to time.
Step-by-step explanation:
When analyzing a velocity vs. time graph, the slope of the graph at any point represents the acceleration of the body. This is because the slope is calculated as the rise over the run, where the rise is the change in velocity (Δv), and the run is the change in time (Δt). In other words, the slope on a velocity-time graph is equal to the rate of change of velocity with respect to time, which is the definition of acceleration. Therefore, among the given options, the slope is identified with acceleration.
It's important to remember that the area under the velocity vs. time graph represents the displacement of the body over a certain time interval, showing how far the body has travelled from its initial position, taking into account the direction as well.