If the molecules are not in water, the randomly moving process shown in this diagram is known as
a) osmosis.
b) diffusion.
c) plasmolysis.
d) active transport.

The correct answer is option b. diffusion.

The diffusion is the transfer of the molecules from one place to another in the direction of the particle gradient. In the process of diffusion, the net movement of the molecules to place of lower molecule concentration.

The osmosis can be defined as the flow of the water molecules along a concentration gradient. the plasmolysis causes the movement of the water molecule from the plant cell due to the contraction of the protoplast. The active transport takes place when the molecules move from a region of lower to higher concentration. Hence, a, c, and d options are incorrect.