Movement of the particles across the membrane stops when the concentration gradient no longer exists, the particles will continue to diffuse due to random motion

Once the concentration gradient no longer exists, particles will continue to diffuse due to random motion.

Explanation:

When there is a permeable membrane between two solutions with different concentrations, the concentration gradient will go from the compartment with more particles to the one with fewer particles to valance the concentrations on both sides of the membrane. Once the concentrations are equal, particles will still randomly move from one side to the other, but the number of particles that move to one side is almost the same as the number of particles that move to the other, so there is still valance and the same concentration in both sides.

interphase

the period of cell growth when the cell synthesizes new molecules and organelles. the cell is not dividing and it constitutes the majority of the time spent in the cell cycle

prophase

changes occur in the nucleus and cytoplasm. the chromatin condenses to form structures (sister chromatids) visible with a light microscope and the mitotic spindle begins to form, but the nucleus is still in tact

prometaphase

the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the sister chromatids

metaphase

all the cell's duplicated chromosomes are lined up at an imaginary plane equidistant between the poles of the mitotic spindle

anaphase

begins when sister chromatids separate from each other and ending when a complete set of daughter chromosomes arrives at each of the two poles of the cell

telophase

the daughter nuclei form at the two poles of a cell

cytokinesis

the division of a cytoplasm to form two separate daughter cells. usually occurs during telophase during mitosis. this and mitosis make up to mitotic (m) phase of the cell cycle

i believe your answer would be c.. : )