Answer:
D
Explanation:
D. My, there were a lot of letters on the subject!
-the word "My" shows a reaction to seeing a lot of letters on the subject so is an interjection
A. -My-. letter to the editor was published today.
B. I expressed -my- ideas about the new freeway
C. I could not believe -my- eyes
-for A,B,C this "my" shows possession my letter, my ideas, my eyes
