A critical part of homeostasis is the tranfer and intake of molecules (whether necessary or not). It is important for the cell to be able to bring necessary nutrients immedriately where it needs to and to be able to dispose of harmful byproducts of the cell process. It is equally important to be able to regulate water concentration. Smaller cells have a bigger surface relative to their volume (their surface scales with R^2 while their volume with R^3 where R is the radius of a cell) and thus exchanges along the cell membrane are favored in comparison to larger cells that need a lot of exchanges but have proportionally less membranes area. While A is not necessarily true, C is definitely true and thus the correct answer.
