Answer:
D. a period of political instability
Step-by-step explanation:
D. a period of political instability is the answer because the Mexican-American War resulted in the loss of a significant amount of territory for Mexico. This territorial loss led to internal conflicts and power struggles within the country. The Mexican government faced challenges in dealing with the consequences of the war, which resulted in a period of political instability characterized by coups, uprisings, and regime changes.