Which one of the following statemetns is correct?
(a) Extensive use of chemical fertilizers may lead to eutrophication of nearby water bodies
(b) Both Azotobacter and Rhizobium fix atmospheric nitrogen in root nodules of plants
(c) Cyanobacteria such as Anabaena and Nostoc are important mobilizer of phosphates and potassium for plant nutrition in soil
(d) At present it is not possible to grow maize without chemical fertilizers