Question

jenna is testing how high blood sugar levels affect athletic performance. which variable is the independent variable?
athletic performance, because it is manipulated by jenna
athletic performance, because it is measured by jenna
blood sugar level, because it is measured by jenna
blood sugar level, because it is manipulated by jenna

Explanation:

In an experiment, the independent variable is the one that is manipulated by the researcher. Here, Jenna is manipulating blood - sugar levels to see its effect on athletic performance.

Answer:

D. Blood sugar level, because it is manipulated by Jenna