Answer:
C. Mexican desire to annex Louisiana
Step-by-step explanation:
This started with Texas disagreeing with the Mexican government, as Texas wasn't part of the United States at this time. When Texas eventually did become a state of the United States, Mexico did not like this and had numerous disagreements over where the border actually was, and who had what. Along with this, America did want California, which Mexico ended up selling to the United States, along with a couple other current states, in the Treaty of Guadalupe Hidalgo. The Mexican desire to annex Louisiana had nothing to do with the causes of the Mexican-American War.