Mark the letter A, B, C or D on your answer sheet to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questions from 13 to 17.

a. Nam: I have a big exam tomorrow and I haven’t finished revising yet.
b. Anna: Don’t worry. I’m sure you’ll do well. Just try to get a good night's sleep.
c. Anna: Hi. You look worried. What's the matter?