________ can vary from culture to culture and are socially acceptable ways of showing emotion in public settings.

A) Phonemes
B) Facial grids
C) Display rules
D) Expressional norms

Display rules are culturally specific norms that dictate what emotions and which expressions of those emotions are appropriate in certain situations. They can vary from culture to culture and even from subculture to subculture within a given society. Phonemes are the smallest unit of sound in language, facial grids are not a recognized term in psychology or sociology, and expressional norms are not a commonly used term in the field of emotions and social behavior.