The correct answer is: C: Y'all don't be late. This is slang because word "You" is shortened to "Y", so instead of "You all", there is just: "Y'all". By definition, slang consists of a lexicon of non-standard words and phrases in some language. Use of these words and phrases is typically associated with the subversion of a standard variety (for example: standard English) and is likely to be interpreted by listeners as implying particular attitudes on the part of the speaker. In some contexts a speaker's selection of slang words or phrases may convey prestige, indicating group membership or distinguishing group members from those who are not a part of the group.