A. Citric acid cycle (Krebs cycle)
The organism belongs to the class Archea, which is a domain and kingdom of single-celled organisms, which lack a nucleus, peptidoglycan layer in the membrane, and bears 70s ribosomes. Archea are prokaryotic and are different from bacteria and eukaryotic organisms.
Answer: D. Add water features to private gardens.
Renewable resources are those which can be replenished after one or subsequent uses. Examples include oxygen, fresh water, solar energy and biomass. Adding water features to private gardens can be a mode of replenishing freshwater. A system which can absorb the water which is being supplied to plants in the garden through soil and collect this water as a reservoir in the form of groundwater.