Answer:
C. Regretful
Step-by-step explanation:
-Nostalgic is when someone misses a moment from the past.
-Hopeful is when you expect something good for the future.
-Regretful is when you feel bad for something you did.
-Excited is whe you feel happy about something.
According to these definitions and the passage, the answer is that the narrator's tone is regretful because he/she had to leave Hidaya and couldn't go to a public school with friends because his/her Mom and Dad insisted that had to go to a private school.
The other answers are not correct because the narrator is talking about the past, not the future. Also, he is not talking about missing something and doesn't feel happy.