What is an example of a microorganism acting in a harmful way? a) fungi decomposing waste. b) protozoa causing disease. c) bacteria aiding digestion. d) yeast causing bread to rise.

B. Protozoa causing disease

The key word in the question is harmful way. A is wrong because it actually helps the environment by giving it nutrients when it decomposes the waste. C. is wrong because bacteria aiding in digestion is a must needed thing for our health since it can help rid bad ingredients in our food. D. is wrong because yeast causing bread to rise does nothing to harm people, unless someone is allergic to yeast.

Hope this helps!!!

Protozoa causing disease.

Explanation:

The protozoa causing disease is an example of the microorganism harming the nature and organism near them.

The protozoan infections are parasitic in nature. Most of the prevalent and harmful human disease are caused by the protozoans.

Sleeping sickness, malaria and amoebic dysentery are some of the diseases caused by the protozoans.