This final, stable community is called as climax community because, unlike communities earlier on in successional process, it doesn?t change much in composition from year to year succession has reached its climax. Hence, correct answer is option C.

A biogeochemical cycle or inorganic-organic cycle is a circulating or repeatable pathway by which eir a chemical element or a molecule moves through both biotic (bio-) and abiotic (geo-) compartments of an ecosystem. 

Pyramid of biomass is graphical representation to determine total living material present at each trophic level. Since re is 90% reduction in biomass at each trophic level, producers exhibit maximum biomass in a terrestrial ecosystem. In given pyramid, producers are represented by level 5 exhibiting maximum biomass. Thus, correct answer is E. 

Rate of production of organic matter in an ecosystem is called Gross Primary Productivity (GPP). When we subtract respiratory losses (R) from GPP, we get Net Primary Productivity (NPP). 
Nature provides various biotic and abiotic factors to enhance rate of Gross Primary Productivity. Hence, it can be said that nature tends to increase gross primary productivity. 
But human beings need to make optimum utilization of biomass produced. This is achieved in various ways; like harvesting crop at right time and plucking fruits at right time. If fruits will be left on tree for a longer time, it will result in higher respiratory losses. A higher respiratory loss will reduce NPP. By plucking fruits at right time, man tries to increase net primary productivity.