The answer is (B. Medium) because it has to travel through the ear drum evenly without busting it. Hope this helped :)
B. Cell wall and a central vacuole
The cell wall is a rigid structure that surrounds the cells and allows plants to stay upright. Animal cells are more fluid.
The central vacuole is a large region in the cell that stores nutrients and fluids. Many cells, including animal cells, contain vacuoles, but most are small, and only plant cells contain large central vacuoles.
Hope this helps!!
