A. not to be late
B. to be late
C. don’t be late
D. None of these
🧠 Explanation:
In the sentence “The teacher told us __,” the most appropriate completion is “not to be late,” reflecting the teacher’s instruction. Understanding reported speech is vital for English learners, as it ensures accurate communication of commands or advice. For students or writers, mastering this grammar rule enhances clarity in writing and speaking, making it a key topic for improving language skills in academic or professional settings.