Final answer:
Option (C), The most important characteristic of systems of stratification is their degree of flexibility, which determines the possibility of social mobility within a society's social hierarchy.
Step-by-step explanation:
One of the most important characteristics of systems of stratification is their degree of flexibility. This refers to the extent to which individuals have the opportunity for social mobility within a stratification system. Stratification systems such as caste and class vary significantly in terms of flexibility.
Caste systems are typically closed and do not allow for much, if any, social mobility due to their ascribed statuses, which are fixed from birth. On the other hand, class systems are more open and can be influenced by individual achievement, allowing movement between different social classes or strata.
Meritocracy represents an idealized version of an open system where social mobility is based solely on personal ability and effort, though a pure meritocracy has never fully existed. Different stratification systems, whether closed or open, reflect and are shaped by the cultural values and beliefs within a society. These systems can greatly influence an individual's power, prestige, and access to resources.