Which punctuation is often confused with quotation marks but serves a different purpose?

Apostrophes are the correct choice, as they are frequently confused with quotation marks due to their similar appearance in written text. However, they serve entirely different grammatical purposes. Quotation marks are used to indicate direct speech, quotations, or to highlight specific words or phrases. In contrast, apostrophes are primarily used to show possession (for example, "Sarah's book") or to form contractions (like "can't" for "cannot"). Understanding the distinct roles of these punctuation marks is essential for clear and effective writing. The other options do not have a close resemblance to quotation marks or serve a similar purpose, making them less likely to be confused in everyday usage.