Answer:
The correct option is C.
C) American settlers rejection of the provisions of the Mexican immigration policy
Step-by-step explanation:
When Mexico gained independence from Spain in 1821. their government allowed the American settlers to occupy the land in its northern side, which was previously occupied by native American tribes.
In the coming years, the settlers kept on coming to the area and started to outnumber the Mexicans. The Mexican government feared that the USA might take it under its control due to a huge population of American settlers, so in 1830 they stopped any further immigration of Americans and reinstated the tariffs, which were suspended before.
This escalated the conflict between Mexican government and American settlers.