D: National Security
All of the others are a form of government and national security is a form of protection provided by the government
Answer: A. The exportion of crops.
Explanation: The Southern states had an agricultural economy and this was why they relied so heavily on enslaved labor. They exported what are called cash crops, such as cotton.
The correct answer to this open question is the following.
The two settlements that were not considered part of Texas in the 1820s, since they were not part of Texas, were Laredo, which was part of the Mexican state of Tamaulipas, and El Paso, which was part of the Mexican state of Chihuahua.
At that time the region of Texas was called Mexican Texas and was comprised of the territories of Texas and Coahuila. This period started in 1821 and ended in 1836 when Texas gained its independence from Mexico. The Republic of Texas existed from 1836 to 1845, when on December 29, 1845, Texas entered the Union.
World War 1 was not fought in Africa but African Americans were NOT allowed to fight with white people.