(a) they are made of materials with lightweight

(b) they are made of toxic materials

(c) they are made of biodegradable materials

(d) they are made of non-biodegradable materials

Correct option – ( d )

Explanation for correct option – disposable plastic plates are made by the material which is non – biodegradable in nature . After some time it starts piling up and harms the environment .

Hence correct option is they are made of non-biodegradable materials