Final answer:
Social stratification is a hierarchy that ranks people in society. Caste systems, which are closed, make hereditary membership the reason for their lack of social mobility. Meritocracy offers the most social mobility based on individual achievements.
Step-by-step explanation:
Social stratification is a system by which society ranks categories of people in a hierarchy. In this system, some people may have higher status and power than others, and this stratification can affect various aspects of a person's life, including occupation, income, and education. Stratification systems can be open or closed.
A caste system is a closed stratification system where individuals are born into their social standing and have limited opportunities to change it. The specific factor that makes caste systems closed is b. Hereditary membership. These systems do not allow for social mobility, meaning people remain in the social class where they were born throughout their lives. Occupations, marriage partners, and housing are determined by one's caste, not by individual talents, interests, or potential.
In the context of social mobility, a meritocracy is the most open system, where individuals can move up or down the social hierarchy based on personal merit and achievement. However, a pure meritocracy has never truly existed. Unlike a caste system, social mobility in meritocracy and class systems are influenced by a combination of ascribed and achieved statuses.