Which one of the following statements is correct?

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Rhizobium fix nitrogen in root nodules of legumes, while Azotobacter is a free-living nitrogen-fixing bacterium. Anabaena and Nostoc are not mobilisers of phosphates. Anabaena is a filamentous cyanobacteria, involved in nitrogen fixation. Extensive use of chemical fertilizers may lead to eutrophication of nearby waterbodies. Related Theory Eutrophication or more precisely hypertrophication, refers to enrichment of a water body with nutrients, usually with an excess amount of nutrients. This process induces growth o