Which statement best describes the main function of an
argumentative essay?

The main function of an argumentative essay is to show that your opinion about some phenomenon is correct or more truthful than others.

Explanation:

I would say that by not using language correctly we can give incorrect meaning to our words and language has the power to influence people and to stir people to action if used properly, so I agree with Orwell in that sense. I would say though that I disagree that language is not well used in politics as there are many examples of powerful language like Martin Luther King's speech of I had a dream which stirred many Americans to support the civil rights movement of the '60s and early '70's for example or the poetry of Muhammed Ali to poke fun at his opponents and also to show that he had no quarrel with the Vietnamese.