Final answer:
The distance the car rolls is the dependent variable and the angle of the board is the independent variable.
Step-by-step explanation:
The correct statement is b) The distance the car rolls is the dependent variable and the angle of the board is the independent variable. In the given scenario, the distance the car rolls is dependent on the angle of the board. By changing the angle of the slant, you are manipulating the independent variable (angle) to observe how it affects the dependent variable (distance). This relationship can be graphed with the angle on the x-axis and the distance traveled on the y-axis.