The best answer is A
Diffusion is said to be the movement of particles, molecules ions fromĀ a region where they are more concentrated to a region where they are less concentrated.
Diffusion does not require a semi - permeable membrane and is purely dependent upon the free energy of the diffusing substance only.
Ink particlesĀ spread (diffuse) from the drop ofĀ ink where they are moreĀ concentrated Ā to all the part of the water in theĀ beaker until they are evenly distributed, thus reaching a state of equilibrium.