The correct response is: "These rebellions were grounded in animosity between the criollos and peninsulares that was based on social and economic issues."
The criollos (creoles), who were of Spanish descent but born in the Americas, often faced discrimination and exclusion from high-ranking positions held by the peninsulares, who were born in Spain. This created significant social and economic tensions that contributed to the rebellions in Spanish America during the early nineteenth century.