Final Answer:
It's the factor intentionally changed or manipulated to observe its effect on the dependent variable, which is the extent of damage to the car. Therefore the correct option is B. The Volume of the Car Stereo.
Step-by-step explanation:
The independent variable is the one manipulated or changed intentionally in an experiment. In this scenario, the volume of the car stereo is what's being altered to observe its effect on the car.
The extent of damage to the car (option A) might vary due to changes in the volume, making it the dependent variable affected by the independent variable, which is the volume of the car stereo.
The car stereo brand (option C) and the car model (option D) are not directly altered or manipulated in this scenario. They might have an impact on the outcome, but they are not the variables being deliberately changed. Therefore, they are not the independent variables.
Therefore the correct option is B. The Volume of the Car Stereo.