Which example best demonstrates diffusion? A. cellular movement
B. an amoeba engulfing a bacterium
C. the dispersal of dye in a beaker of water
D. a contractile vacuole removing excess water

A contractile vacuole removing excess water is the correct answer.

Diffusion is defined as the movement of particles from a region of high concentration to a region of lower concentration. Diffusion occurs in both liquids and gases which is an important process for living organisms.

In contractile vacuole, water moves from higher concentration region to lower so we can conclude that a contractile vacuole removing excess water is the correct answer.

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chlorophyll a: this is the most abundant pigment in plants. chlorophyll a absorbs light with wavelengths of 430nm(blue) and 662nm(red). it reflects green light strongly so it appears green to us.

i think the answer is

mass