Plant produces food material in the process of photosynthesis in the leaves. The food that is produced in the form of glucose (sugar) is transported from the leaves to other parts of the plants such as roots, stem and seeds with the help of water. When the glucose reaches to the storage part it is stored in the form of starch.
For example, in carrot and potato food is stored in roots while in sugar cane the food is stored in the stem.
I believe the correct answer would be B. Semipermeable means that it allows certain substances to pass through, and certain other ones to not pass through. So given all of your options, I would say that B makes the most sense. Hope this helped!