Answer:
Letter C. The reader only knows what one character is thinking or feeling--the speaker or narrator.
Step-by-step explanation:
A first-person narrator uses first-person pronouns such as "I" and "me" and gives us his / her own perspective on things. Narrating from a first-person perspective is a technique employed to create a bond between the narrating character and the reader, as well as to focus on that character's emotions and thoughts. When the first-person is used, readers get to know much more about the narrator-character, but less of the others, unless the information is directly obtained by the main character somehow. Freedom is also limited, since readers can only "accompany" the narrator, not knowing what that narrator doesn't know. Thus, if there is a parallel event in the story, it will only be revealed to readers if it is revealed to the narrator.