Final answer:
Polycentrism is the correct criterion for adaptation when dealing with foreign countries because it involves adapting to the host country's culture, unlike ethnocentrism, which is the belief in the superiority of one's own culture.
Step-by-step explanation:
The criterion for adaptation when dealing with individuals, firms, or authorities in foreign countries among the options given is Polycentrism. Polycentrism refers to a company or individual's approach to international operations where they adapt to the culture and practices of the host country.
This can be contrasted with ethnocentrism, which is the belief that one's own culture is superior to others, and can harm international relations and business ventures. As sociologist William Graham Sumner (1906) described, ethnocentrism is an attitude that can cause individuals to judge other cultures based solely on the standards of their own culture, potentially leading to misunderstanding and conflict.