Answer:
The answer is C.
Step-by-step explanation:
Texas wanted to get it's state boundaries farther west so they could occupy more territory. The main reason to this is because Texas was bought by the United States in 1845 and lost much of it's land to the most western states (Mainly New Mexico, Colorado, and Oklahoma) and some to Mexico.
I know I answered a bit late, butI hope this helps people in the future.