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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the answers are a and c