Answer:
Correct answer is Texas.
Step-by-step explanation:
Texas is the correct answer because although Americans wanted to include this territory in the agreement it was something that was not acceptable for Spain. Actually, Texas went to the hands of Mexico, who was an independent country back that and that is why Mexico is not correct answer.
Canada is also not correct answer as Canada had nothing to do with this agreement.
Oregon County is not correct as this was a question between United States and Britain.