The plastic bag is permeable to which substance iodine or cornstarch/water solution ?

Question

The plastic bag is permeable to which substance iodine or cornstarch/water solution ?

Answer 1

Which plastic bag?  The most likely answer is the iodine because cornstarch is a much larger molecule than iodine. So, if the bag is semipermable, then it's likely the smaller molecule can cross.

Answer 2

And the bag is almost certainly permeable to water molecules.