Which of the following is an example of a correctly punctuated sentence?

The sentence "I asked her, 'Since when are you an Elvis fan?'" demonstrates correct punctuation for several reasons. First, it correctly places a comma before the quotation to indicate the beginning of a direct quote. This is a standard rule in English punctuation; when introducing a quote, a comma is typically required unless other punctuation marks are more appropriate.

Additionally, the quotation itself is properly capitalized and presented. The first word of the quote, "Since," begins with a capital letter, as it is the start of a complete thought. This adherence to capitalization rules is essential for maintaining proper sentence structure.

Furthermore, the question mark at the end of the quoted section is placed inside the quotation marks, which aligns with punctuation conventions for direct questions. In English, when a quoted sentence is a question, the question mark is included within the quotation marks.

Overall, the combination of the correctly placed introductory comma, proper capitalization of the first word in the quotation, and the accurate use of the question mark encapsulates why this sentence is punctuated correctly.