Which of the following purposes do you think political parties serve

they divide and separate a lot of different people who have different views

Explanation:

I'm not positive, but that's definitely the best of the options

Not possible

Explanation:

The essay you are to write is your own opinion and since there is no one else like you, it is simply not possible to write for you what can be written by you.

What I suggest is that you look at international events and pick one that truly interests you and write about it.  You'd be surprised how much better it is to write in your own words than to have someone else pick an event and write it for you.