What does style refer to in the study of stylistics? （ ）

A、A person’s distinctive language habits, the set of individual characteristics of language use.
B、Some or all of the language habits shared by a group of people at one time or over a period of time. by a group of people at a given time.
C、The effectiveness of a mode of expression
D、A characteristic of ‘good’ or ‘beautiful’ literary writings.