Which of the following would cause a decrease in the rate at which a bacterium is able to acquire nutrients from its surroundings through diffusion? An increase in size of the bacterium due to a period of growth
O
An increase in tonicity of the bacterium's environment
Fission of the bacterium into two daughter cells
Growth of the bacterium's flagella from the basal body

B. An increase in tonicity of the bacterium's environment

Explanation:

An increase in the tonicity of the bacterium's environment will decrease the diffusion rate.

Tonicity affects the osmotic regulation of the cell and as tonicity increases the cell becomes hypertonic and water moves out of the cell.

So, an increase in tonicity makes it difficult to get water in the cell and the cell will become dehydrated due to lack of water.

Hence, the correct option is "B."