Answer:
A. the amount of force on the spring scale
Step-by-step explanation:
In every experiment we make some changes to the input variable and we measure the effect of change as the outcome variable
Input variable is controlled by us, but the output variable cannot be changed directly, it can be changed by changing the input variable.
In this experiment Michelle changes the angle θ between the ramp and the ground to find its effect on force required to lift.
The force required to lift is the weight of the object
Since, we change the angle, it is the input variable
and since, we measure the weight from the scale, it is the output variable