Final answer:
Civilizations are characterized by social classes, cities, and job specialization, with each playing a core role in the development of stable and stratified societies with diverse professions and large-scale architectural accomplishments.
Step-by-step explanation:
The characteristics that define civilizations include a. Social classes, c. Cities, and d. Job specialization. Culture, although important, is more of a broader aspect that encompasses these characteristics and is not limited to civilizations, as even non-civilized societies have cultures.
Social classes emerge as societies develop and stratify, often with farmers and laborers at the bottom and rulers and religious leaders at the top. Large-scale architecture and monuments, another great indicator of civilization, are made possible through the job specialization that arises when a society becomes sedentary and well-fed.
This specialization includes a variety of professions, from artisans to priests. Moreover, cities serve as the epicenters of civilizations, typically located along large rivers and supported by surplus agriculture. The concentration of people in cities aids in the development of job specialization and social classes, as well as in the building of structures like the ziggurat in ancient Sumer.