Concept:Biodegradable materials can be broken down by microorganisms and natural processes.
Non-biodegradable materials, like synthetic polymers, resist such decomposition and persist for a long time.
Explanation:Cotton bag is made from natural plant fibres, so it can be easily decomposed by microbes.
Paper bag also comes from wood pulp and degrades readily in the environment.
Hides and skin bag is an animal product, and it can also be acted upon by decomposers.
A polythene bag is a synthetic polymer made from petroleum products.
Microorganisms do not easily attack the long polymer chains of polythene.
Therefore, a polythene bag remains in the environment for many years without breaking down.
Among the given options, the polythene bag is the material that is not easily biodegradable.
Answer:A. Polythene bag