what does it mean when a teachers adds a “excerpts in isolation” comment

Which sentence is an example of first person narration? a. guess where i'm going? martin's sister said as she ran out of the house. b. where are you going? i asked my sister as she ran out of the house. c. where are you going? you ask your sister as she runs out of the house. d. where are you going? martin asked his sister as she runs of the house.