Answer - A - Cotton was a primary cash crop
Reasoning - First we have to look at the question (Southern Economy). Which already gives you a hint that yes all the other industrialization and delivery help with money. But not as cotton was a base line for cash crop and its was the foundation to the south. Without cotton being a primary cash crop or white gold. Will equal to no money for the south economy. Yes A is the correct answer.
The correct answer in the missing blank is known as "separation".
The six degrees of separation is known as a theory in social networking wherein it states that a person can be connected anyone in the world, no matter how far, through a process of acquaintances, which possesses not more than five mediums.
President Nixon is the president who nominated him.