Crystals of dye, when placed in a beaker of water, eventually spread evenly throughout the water. This is an example of

a
diffusion.
b
osmosis.
c
active transport.
d
phagocytosis.

a) diffusion.

The correct answer is a) diffusion. Diffusion is the process by which particles move from an area of higher concentration to an area of lower concentration. In this case, the dye particles move from an area of higher concentration (the crystal) to an area of lower concentration (the water) until they are evenly distributed throughout the water.