The correct answer is Launch angle
Explanation:
The Independent Variable can be easily identified because this is the factor or variable the researcher modifies. In this case, this term applies to the angle because as part of the experiment the student changes the angle multiple times to test how the maximum height changes. Moreover, the maximum height would be the dependent variable as it is the main factor and it changes or depends on other variables including the angle. Thus, it can be concluded the independent variable is the launch angle or the angle from which the ball is launched.
