What best describes a system where people can change their social status based on their efforts?

A system where people can change their social status based on their efforts is best described as an open system. In an open system, social mobility is achievable, allowing individuals to improve or change their social standing through their actions, education, work, and other achievements. This type of system promotes the belief in meritocracy, where success is based on individual talents and hard work rather than predetermined factors like social class or background.

In contrast, restricted systems, such as caste systems, limit social mobility by assigning individuals to fixed social positions determined at birth, with little or no opportunity for movement between classes. Hierarchical systems may allow for some degree of mobility but often do not grant the same level of access and opportunity as an open system does. Thus, the defining characteristic of an open system is its flexibility and the potential for individuals to elevate their status through personal efforts and achievements.