Final answer:
The belief that one's own cultural practices are superior to those of other cultures, as illustrated by the breastfeeding practices of Cultures A and B, is known as ethnocentrism, not cultural relativism, cultural integration, or cultural diffusion. So the correct answer is option (B).
Step-by-step explanation:
The situation described where people in Culture A breastfeed their children until at least age 3, whereas people in Culture B never breastfeed and consider each other's practices as incorrect, is an example of ethnocentrism. Ethnocentrism is the belief that one's own cultural practices are superior to those of other cultures.
Contrastingly, cultural relativism recognizes that different cultures have different ways of doing things without passing judgment on those practices as inferior or superior. Engaging in cultural relativism requires understanding and respecting these differences and potentially adapting to new values and norms.
This can be challenging when certain cultural practices, like female genital mutilation, are considered harmful or violate human rights. The aim of cultural relativism in anthropology is not to accept all cultural practices as morally equivalent but to foster understanding and form cross-cultural relationships based on respect and insight into diverse cultural behaviors.