Final answer:
The term that best represents a division of society by rank or class is 'Surplus.' Meritocracy allows for the most social mobility. Examples of rigid class structures can be found in historical contexts such as Plato's Republic or the Indian Caste Systems.
Step-by-step explanation:
Understanding Social Stratification
To address the student's question, the word that best fits the definition 'A division of society by rank or class' is d) Surplus. Surplus is linked to the creation of social stratification in early civilizations where an excess of goods led to wealth accumulation and, in turn, a hierarchy of social ranks based on wealth, power, and prestige.
Social Mobility within Different Systems
Regarding the question on social mobility, the system that allows for the most mobility is c) Meritocracy. Meritocracy is a social system where advancement is based on individual abilities and merit rather than on birth or privilege. This contrasts with cast systems like the Indian Caste Systems, which lock individuals into social classes from birth.
Examples from Historical and Religious Contexts
In Plato's The Republic, a meritocratic view is proposed, suggesting that society benefits when individuals engage in work they are best suited to. Historical class divisions such as those in the Indian Caste Systems categorized individuals into Brahmins, Kshatriyas, Vaishyas, Sudras, and Dalitas, with little room for movement between classes.