This term was used by southern politicians to describe the importance of cotton to the plantation economy of the south.

King Cotton

Explanation:

The King Cotton term was used by the southern politicians to describe the economy of the South. The southern economy based on the plantation, where planters grew cash crop like cotton. The term was coined before the Civil war because the southern was confident that cotton would save them from war. As Senator James H. Hammond addressed the U.S. Senate by saying cotton is king and no one should dare to make war upon it.

the three roles stated in the dialogue develop the siblings' personalities.

lloyd's personality looks like a trademarketer

dana's personality is afraid from lloyd's behavior and the oldest sister is a decided person who tries to solve any conflict

the answer is to stop cheating on plato