Culture is a way of life. People living in a certain area may have a certain culture.
I'd say this is false, because you cannot possibly memorize everything exactly, let alone such rules. You can always look them up, you don't have to learn them by heart.
Some things you could talk about in your letter are the hazards of litter and polythene. State the reasons why you believe actions should be taken and describe your concerns in your letter. Describe why this is bad for our environment and health. Convince them to see your point of view in the letter by coming from a place of concern, think about health concerns of others. I hope this helps.
D is the best answer. Themes express a life lesson.
