EDTA Is a Metal-Ion "Chelator" That Is Commonly Used to Lower

EDTA is a metal-ion "chelator" that is commonly used to lower the concentration of free divalent cations in solution. In the lab, your friend has cultured a human cell line on elastic membranes that have been coated with fibronectin and attached to a device that can stretch the membrane. She has quantified the binding of talin to integrin under different conditions, and has presented the results in the following schematic graph, which shows the binding in the presence or absence of EDTA in the cell-culture medium. Which experiment (A or B) do you think was performed in the presence of EDTA? Write down A or B as your answer.