Hello there!
Let's take for example plastic, plastic would take a good while for it to decompose. It wouldn't make sense for it to be "food produce" because food does decompose very quickly. Wood could be the answer, but wood wouldn't take that long for it to decompose, all it could use is some constant water and rain, and then the wood would then give old and just decompose. But even thought that is the case, wood cuttings would be the answer.
Vegetable peels would not take a long time.Most likely, they are probably to fastest in this list above. So, based from your options, your correct answer would be (wood cuttings).
(option a) would be your answer.
I hope you found this helpful