Mexico's belief that the Nueces River was the true border between Texas and Mexico led to —
the end of Mexican resistance to U. S. westward expansion
a barrier to the U. S. dream of Manifest Destiny
the river's pollution from U. S. industries
an increase of land area for Texas and the U. S.

a barrier to the U.S. dream of Manifest Destiny

Explanation:

the answer is a

their confiscation of contraband and the sinking if the lusitania

the option which was not a function of missionaries in the northwest was the first one - they established posts for trading furs and other goods.

missionaries were sent around the world to spread religion and their knowledge and others - they were not merchants who sold furs and other goods.