The correct option is D Cattle dung
Biodegradable substances are substances that are easily decomposed by natural decomposers and therefore, they do not cause harm to the environment. Examples: human and animal excreta, plant wastes. Whereas, non-biodegradable substances are those substances that cannot be decomposed by natural decomposers. They harm the environment. Examples: radioactive wastes, chemical wastes like DDT, aluminium cans, plastics, etc. Thus, the correct answer is option D.