which of the following organisms is located only in the 3rd trophic level of the soil food web?\na…

Brief Explanations:

In the soil food web, trophic levels are categorized based on what organisms consume. The first trophic level consists of photosynthesizers (plants). The second trophic level consists of decomposers and mutualists like bacteria and fungi, as well as root-feeders. The third trophic level consists of shredders, predators, and grazers that consume the organisms from the second level. Protozoa are primary consumers of bacteria, placing them strictly in the third trophic level. Nematodes, however, can occupy multiple levels (2nd, 3rd, or 4th) depending on whether they eat plants, bacteria, or other nematodes. Therefore, protozoa are the best fit for being located primarily in the 3rd trophic level.

Answer:

C. protozoa