The area under an acceleration-time graph represents the change in velocity of an object over a given time interval. This means that the correct answer is option 'c' - change in velocity.

Explanation:
Acceleration is defined as the rate of change of velocity. If an object is experiencing constant acceleration, the area under its acceleration-time graph will be a rectangle. The base of the rectangle represents the time interval, and the height represents the acceleration. The area of this rectangle is given by the product of its base and height, which is equal to the change in velocity.

Here's a detailed explanation of each option:

a) Initial velocity: The initial velocity of an object is not directly related to the area under the acceleration-time graph. The initial velocity can be determined from the velocity-time graph or by using other given information.

b) Final velocity: The final velocity of an object is also not directly related to the area under the acceleration-time graph. The final velocity can be determined from the velocity-time graph or by using other given information.

c) Change in velocity: The area under the acceleration-time graph represents the change in velocity. If an object is experiencing uniform acceleration, the area can be calculated using the formula: Area = acceleration × time. This change in velocity can be positive or negative depending on the direction of acceleration.

d) Distance traveled: The area under the acceleration-time graph does not directly represent the distance traveled. The distance traveled can be determined using the velocity-time graph or by integrating the velocity function with respect to time.

In conclusion, the correct answer is option 'c' - change in velocity. The area under the acceleration-time graph represents the change in velocity of an object over a given time interval.