Mark the letter A, B, C, or D on your answer sheet to indicate the sen

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.   

You don‘t try to work hard. You will fail the exam.

• A. A. Unless you don‘t try to work hard, you will fail the exam.
• B. B. Unless you try to work hard, you won‘t fail the exam.
• C. C. Unless you try to work hard, you will fail the exam.
• D. D. Unless do you try to work hard, you will fail the exam.

Unless = If not nên khi dùng Unless, vế đầu chuyển thành dạng khẳng định, vế sau giữ nguyên.