Answer:
The independent variable
Step-by-step explanation:
Because it's independent and not dependent on something else. Your independent variables are the things that remain constant and never change. For example if you did an experiment does the type of glass used to put your water in affect the taste. You would use different glasses which would be your dependent variable. But you would use water for each experiment so the water would be your independent variable in this situation because it stays the same.
(source:quora)
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