I am no expert but I think the correct answer is C.
Answer:
Explanation:crystal size in igneous rocks is determined by how quickly magma or lava cooled to form it.
I think the correct answer from the choices listed above is option B. During diffusion, when the concentration of molecules on both sides of a membrane is the same, the molecules will <span>stop moving across the membrane. This is because equilibrium has already been achieved and there is no more driving force which is the concentration gradient present.</span>