Brownian motion is due to:

A. The random fluctuation of the energy content of the environment.

B. The random movement of pollen granules suspended in water.

C. Thermal noise.

D. The random fluctuation of the energy content of the environment and thermal noise.

B. The random movement of pollen granules suspended in water.

Explanation:

Brownian motion or pedesis is defined as the random motion of particles suspended in a fluid resulting from their collision with the fast-moving molecules in that fluid.

Because the movements of atoms and molecules in a liquid and gas is random, larger particles will disperse evenly throughout the medium. If there are two adjacent regions of matter and region A contains twice as many particles as region B, the probability that a particle will leave region A to enter region B is twice as high as the probability a particle will leave region B to enter A.

B. The random movement of pollen granules suspended in water.

Explanation:

Brownian motion is the irregular movement of particles suspended in a liquid or a gas, and it is usually caused when there is a bombardment of the particles by the molecules in the liquid or gas.

The Brownian motion who was named after Robert Brown, first experimented the random movement of pollen grains in water; therefore the movement of pollen grains or granules suspended in water.