The area under a Velocity-Time graph represents the displacement of an object. If the object is moving in one direction, this is equivalent to the distance covered.

The area under a Velocity-Time graph represents the displacement of an object. If the object is moving in one direction, this is equivalent to the distance covered.

• Acceleration is represented by the slope of a Velocity-Time graph.
• Speed is the magnitude of velocity, which is plotted on the y-axis.
• Average velocity is the total displacement divided by the total time.

Therefore, the correct option is C.

The final answer is $\boxed{\text{C. Distance covered}}$.