Final answer:
The most serious norms in sociological and anthropological terms are mores, which are deeply linked to a group's moral principles and may have legal ramifications, while folkways are less serious norms pertaining to day-to-day etiquette and behavior. Mores and folkways make up what sociologists and anthropologists call the normative system (a).
Step-by-step explanation:
Mores and folkways make up what sociologists and anthropologists call the normative system. Of these two, mores are the most serious while folkways are not as serious and tend to solicit minor sanctions. Therefore, the correct answer is a. Mores; Folkways.
Mores are norms that embody the moral views and principles of a group. They often have a religious foundation, and violating them can lead to serious consequences. The strongest mores are protected with laws and other formal sanctions. Violating mores such as committing homicide, which is punishable by law, is frowned upon and judged by public sentiment.
In contrast, folkways are norms that direct appropriate behavior in the day-to-day practices and expressions of a culture without any moral underpinnings. These can include manners and expected behaviors like etiquette and dress codes for specific situations. They help people to smoothly navigate daily life within a given culture.