Olivia and Caitlyn want to know whether the wind affects how far a football will travel. They have one student go outside to the football field when it is not windy and throw the football 30 times. They measure how far the ball goes using a meter stick. On a windy day, they have the same student go to the football field and throw the football 30 times. Again, they measure how far the ball goes using the same meter stick. What is the Independent Variable?

presence or absence of wind

Explanation:

When establishing a relationship between two variables the effect one variable has on the other is studied. The variable that changes with respect to the other is the dependent variable while the other variable is called the independent variable.

Here the distance the football covers in the presence and absence of wind is studied. So, the presence or absence of wind is the independent variable.

i think the answer is a and b

i wish you luck