Concept:Wildlife and forest conservation improves when people avoid products obtained from animals and trees.
Explanation:Act I, making shoes from crocodile skin, requires killing wild animals and should not be encouraged.
Act III, using elephant tusks for decoration, promotes poaching and directly harms wildlife.
Act IV, using firewood for cooking, increases the felling of trees and leads to deforestation.
Act II, making tables with plastic, uses a synthetic material instead of wood.
When plastic replaces timber, the demand for cutting trees is reduced.
This helps to preserve forests and protect the natural homes of wild animals.
Therefore, among the four activities, only act II supports the conservation of wildlife and forests.
Answer:The act that should be encouraged is II, making tables with plastic.
The correct option is C.