The answer is C. Prices are established by the interaction of supply and demand. It is determined by the supply and demand model where the price occurs at the intersection of demand and supply. The market always favors at this point where the supply is equal the demand since it is the point where they will be able to sell their product without experiencing loss.
One of the main reasons why there were so many political revolutions in the 17th and 18th centuries is because the Enlightenment period had made people call into question the absolute authority of divinity and monarchs--making them instead interested in taking charge of their own political destiny.
Dr.King uses the elements ethos and pathos in his argument of the American dream by being perceived as credible by his audience and using the hope and determination involved with the American Dream to persuade the audience with these emotions (Hope this helps)