Learn English – Punctuation of sentence ending with the word “period” for emphasis

I consider the first to be the most correct, although I would precede the quote with a comma and capitalise the beginning of John's sentence.

John asked her, "Do you have the time?"

I have seen it called, among other things,

• terminal punctuation
• end marks
• end punctuation
• sentence-final punctuation
• sentence-ending punctuation
• terminating punctation

In fact, I have found a similar mix of terminology across fields— music, informatics, linguistics, writing— and across levels from elementary school to postgraduate study, and so will venture to say that there is no single preferred term. You will find several of these terms, and others, used within the Chicago Manual of Style Q&A blog itself.

I think the concept is well-understood among audiences who would care about punctuation in the first place, so my advice is to simply pick one term and be consistent with it.