The correct option is D Monera
Monera - Kingdom Monera includes all the unicellular prokaryotes.
Protista - Kingdom Protista includes the unicellular eukaryotes, which are primarily aquatic and they have a well defined nucleus and various other cell organelles.
Fungi- Kingdom Fungi constitutes a unique kingdom of heterotrophic organisms, which show a great diversity in morphology and habitat.
Plantae - Kingdom Plantae includes all the multicellular, both photosynthetic and non-photosynthetic plants.
Animalia - All the animals are placed under Animalia.
Blue-green algae, the nitrogen fixing bacteria and the methanogenic bacteria are all unicellular and prokaryotes. Therefore, the kingdom which includes the blue-green
algae, the nitrogen fixing bacteria and the methanogenic archaea is Kingdom Monera.