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.

Hi Lucas,
a. I finally managed to fix the bug in my app after struggling for days.
b. I'm writing to share some exciting progress on my coding project.
c. Let me know if you're free to test it this weekend.
d. It now runs much faster and doesn't crash anymore.
e. Your suggestions about the interface were really helpful, by the way.
Cheers,
Anna