The answer that best describes the tone in those lines is b, lonely.
C)the horses drawing the sun
Juliet is addressing the horses drawing the sun. She uses the words "gallop" and "steeds" to describe them. Also, in the background information provided, it says that Phoebus has a "horse-drawn chariot that travels across the sky each day." The sun is not a steed, nor it is plural. The same is true of Phoebus and Phoebus's chariot. Therefore, these options are all eliminated. The horses are the only possible answer.
