Explanation:

- Ethnocentrism refers to judging other cultures based on the standards of one's own culture.

- Studying norms means learning about the unwritten rules that guide behavior in a society.

- Studying subcultures and countercultures involves examining groups whose beliefs or behaviors set them apart from the wider culture.

- Cultural relativism means understanding another culture on its own terms and not judging it solely by the standards of one's own culture. However, none of these specifically means basing knowledge strictly on facts.

The correct answer is:

None of the options listed is strictly about the belief that knowledge must be based on facts; the term you are looking for is likely "empiricism."