The best answer here is B: he shared the theme of Plutarch's narrative. If you look at the two excerpts, you see that while he kept some phrasing the same, it isn't exactly alike (which is why A isn't the best answer here). However, by rephrasing slightly, Shakespeare has allowed the basic understanding and meaning of Plutarch's writing to bleed into the play Julius Caesar. C and D do not make much sense in reference to the question because he has rephrased Caesar's comment slightly and Shakespeare did not include only one small part.
They talk about carrots and beets. After that they say "However." Then they talk about how carrots are long and slender. "while" beets are round and red.
