Answer:
The right answer is B) the annexation of Texas to the United States.
Explanation:
The Texas annexation took place in 1845. There was also a dispute over where Texas ended , whether at Río Nueces or at the Río Grande (Río Bravo for Mexicans). These were the direct causes of war which erupted in April 1846 and ended in 1848. The US won a decisive victory and took more than 500,000 square miles (1,300,000 square kilometers ) of Mexican territory.