Question

what does the slope of a line on a distance - time graph represent?
time taken to travel a specific distance
mass of the object
speed at which an object is traveling
distance traveled over a specific time period

Explanation:

The slope of a line on a distance - time graph is calculated as $\frac{\text{change in distance}}{\text{change in time}}$, which is the definition of speed.

Answer:

C. speed at which an object is traveling