To Test for the Presence of Starch, Iodine Can Be

To test for the presence of starch, iodine can be used. A positive reaction results in a black color. A dialysis bag filled with starch solution and secured on both ends is placed in iodine solution. After 30 minutes the dialysis bag appears black. Based on this information, what most accurately describes what happened?

A) Due to its size and polarity, starch was able to exit the dialysis bag and interact with the iodine solution.
B) Due to its size and polarity, iodine was able to enter the dialysis bag and interact with starch.
C) Over time, both iodine and starch are equally distributed throughout the two solutions.