Answer: D. I never knew that I could be so happy
Explanation: The sentence that is an example of the first-person narrative is I never knew that I could be so happy. The first-person narrative is a point of view in which the narrator uses the pronouns I or We. The point of view tells us who is telling the story. In the first-person narrative, the narrator can be switched to different characters to introduce a broader viewpoint, as the reader can only see through the narrator's eye and thoughts.