Answer:
Correct answer is Fights with Native Americans
.
Explanation:
First option is not correct as Texas was a part of Spain until 19th Century. Then, for a short period of time Texas was a part of Mexico, but then was a republic from 1836 until 1845, when it finally entered United States.
The other option is correct as they were leading many wars there against the Natives, especially in the 19th Century with Comanches.
Last option is also not correct as this was not a problem for them.
