The following experiment was designed to test whether different concentration gradients affect the rate of diffusion. In this experiment, five solutions (0% $KCl$, 1% $KCl$, 2% $KCl$, 3% $KCl$ and 4% $KCl$) were tested under identical conditions. 20 mL of 0% $KCl$ were put into a bag formed of dialysis tubing that is permeable to $K^+, Cl^-$, and water.
The same was repeated for each $KCl$ solution. Each bag was submerged in a separate beaker containing 250 mL of distilled water. The concentration of $KCl$ in mg/L in the water outside each bag was measured at 30-second intervals. The results from the 2% $KCl$ bag are shown in the table below.
Which of the following graphs below BEST represents the data for the 2% $KCl$ solution?
|Time (seconds)||$KCl$ (mg/L)|