Of the Following, Choose the Best Topic Sentence for a Narrative

Of the following, choose the best topic sentence for a narrative paragraph.

A) On my first day as a volunteer at the hospice, I learned that I could actually make a difference in a stranger's life.
B) Singing karaoke is my secret passion.
C) My Spanish teacher in high school was a sarcastic person who hid a caring heart.
D) I found out that making a healthy holiday dinner is easy if you follow these steps.