Read the following statements.
(i) Removal of tigers from an area will result in increased growth of vegetation of that area.
(ii) Organisms at each trophic level depend on those at the lower trophic level for their energy demands.
(iii) Food chains are sustained by producers and decomposers
(iv) In a food chain , some organism like sparrow operates at one trophic level only.
Select an option which shows CORRECT statements.