Which of the following statements represents proper spacing after punctuation?

The correct response reflects the APA style guidelines that specifically address proper spacing after punctuation. In APA format, spacing conventions dictate that one space should follow punctuation marks that occur at the end of sentences, which relates to the option concerning all punctuation marks at the end of sentences. This alignment with modern practices is essential for clarity and readability in academic writing.

Additionally, using a colon correctly in the text also involves the consideration of spacing. In APA style, it is standard to have one space after a colon when it is used to introduce a list, a quotation, or an explanation. This adherence to spacing practices enhances the overall format of the text and ensures consistency throughout the work.

The correct identification of colons and periods as being aligned with APA spacing rules underpins the rationale for the answer. By recognizing that both components a and c align with APA formatting guidelines, it supports the conclusion that option D is an accurate representation of correct spacing principles in APA style.