A) First person POV is when the person whom the events are happening to is telling the story, or someone in the story is telling the story. The story is in first person when the narrator uses words like "I" "we" "us" or "me".
B) Third-person omniscient is where the narrator knows all of the charaters' feeling but isn't in the actual story. You know when the story is told in third-person omniscient because the narrator will tell you the character's emotions, feelings, or inner thoughts.
C) Third-person limited is when the narrator isn't in the story but can tell you the thoughts and feeling of the main character. You can tell when a story is third person limited because pronouns like "she" "he" or "they" are used, but they don't know much more.