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. Try to work hard. Otherwise, you will fail the

Unless you try to work hard, you will fail the final exam.

Unless you don't try to work hard, you will fail the final exam.

If you try to work hard, you will fail the final exam.

As long as you try to work hard, you will fail the final exam.