Dear [Teacher's Name],
I hope this message finds you well.
I understand that Da-sol couldn't take the retest for Unit 5 due to a delay,
and I kindly ask if it would be possible to allow her to retake it.
Her GPA is crucial for her university application in Korea.
Unfortunately, I had to leave home for three weeks to undergo eye surgery,
which is why she missed the exam.
I would greatly appreciate your understanding and support in this matter.
Thank you for considering my request.
Best regards,
[Your Name]