The correct option is C Polythene
Jute, cotton and coir are natural fibre obtained from animals and plants. These fibres do not release poisonous gases on burning. Also, these can be easily decomposed by microbes i.e. these are biodegradable.
Polythene, on the other hand, is a synthetic fibre as it is made from chemical processes. It releases harmful gases on burning. Also, it is non-biodegradable as it cannot be decomposed by microbes.
Thus, bags made of polythene are less environment-friendly as compared to jute, cotton, silk and coir bags.