Which sentence uses correct grammar and punctuation?

• A. This sentence is incorrect grammar.
• B. This sentence has punctuation error.
• C. This sentence contains multiple errors,one comma splice.
• D. This sentence is grammatically correct and properly punctuated.

Answer: (D)

Grammar and punctuation correctness is what this item checks. The best sentence clearly states that it is grammatically correct and properly punctuated, using a straightforward subject-verb structure and paired adjectives that flow naturally. It begins with a capital letter, ends with a period, and uses standard modifiers without extra or misplaced punctuation, making the meaning clear and unambiguous. The other sentences falter in small but important ways: one makes an awkward self-reference about its own grammar, another omits the necessary article, and the last has spacing and punctuation issues that disrupt readability. Taken together, the self-describing, well-formed sentence demonstrates proper grammar and punctuation.