Explanation
Correct answer: B.
Choice B is the best answer because it presents a question that the text is attempting to answer: why has the pronoun "y’all" become more widely used in the US? The text begins by explaining where and how the plural pronoun "y’all" originated and then goes on to state that its use has been rising in popularity, even in areas outside of its place of origin. The text then attributes this rise in popularity to the fact that many varieties of English do not have a pronoun to address more than one person, and thus "you" must function as both a singular and plural pronoun.
Why the other choices are wrong
Choice A
Choice A is incorrect because while the text states that "y’all" is used as a plural of "you" in English, it does not discuss other plural forms of the word.
Choice C
Choice C is incorrect because while the text discusses the general origins of the pronoun "y’all," it does not state when the use of the pronoun was first recorded in the English language.
Choice D
Choice D is incorrect because though the text addresses the use of the pronoun "y’all" within English-speaking communities in the US, it does not address its use outside of that geographic area.