Question

Independent Variable help

Answer 1

Mr. Jones has run out of dialysis tubing but would like his students to model the permeability of cells. He asks students to design an experiment to test which brand of plastic sandwich bags will allow molecules to pass through. Mr. Jones gives the students a list of available supplies which includes: starch, iodine, water, glassware, and 3 different brands of sandwich bags. What is the independent variable in the experiment?

A. Water
B. Iodine
C. Starch
D. Sandwich bags


I think it is d but i am not 100% sure