Answer:
The membrane excluded the starch molecules, but the iodide ions diffused through
Explanation:
The diffusion of substances always occurs from the region of higher concentration to the region of their lower concentration.
According to the given information, starch is a large macromolecule. Reaction of iodide and starch turns iodide ions dark blue. Since the side A of the container turned dark blue, it means that iodide ions diffused through the membrane from side B to side A. It turned the side A dark blue.
If starch would have diffused from side A to side B through the membrane, the side B would also have turned dark blue. However, side B had a brown solution. Therefore, the large molecules of starch were not allowed to pass through the membrane.