Answer:
B.Creoles who largely benefited from the caste system joined with Spanish forces to fight rebels from less powerful castes.
Step-by-step explanation:
The caste system in colonial times created a large and perfeted way of racial segregation for the mexican people, it was a well established pyramid that allowed you to get a job, an education, and other things, own land, and Creoles were the sons of Spanish born in America, they weren´t considered Spanish, but had a high role in the caste system, they were able to hold political positions and other important roles, since they were largely benefited from this caste system they joined with the spanish to fight the less priviledged races.