Answer:
Thought it was rewarding and fun to help people.
Step-by-step explanation:
The sentence selected above would be ideal only to be placed in the introduction of Carmen's personal narrative, because it determines an appropriate thesis statement to show her position in relation to volunteer work, as well as supporting her justification for engaging in this type of activity.
Furthermore, among the response options presented, this is the only one that can be added to the introduction in a coherent and cohesive way, with the other options being more appropriate for the body of the narrative.
We must not forget that the thesis statement is usually part of the end of the introduction and presents the author's opinion and position in relation to something.