() is a situation where two varieties of a language exist side by side throughout the community, with each having a definite role to play.

A. The language a person uses reveals his social background.
B. There exist social norms that determine the type of language to be used on a certain occasion.
C. How does the human mind work when people use language.
D. To investigate the social aspects of language.

A. style
B. dialect
C. register
D. pidgin