Question

nurses coarse, motherly character provides a foil for
romeo, who is young and emotional
mercutio, who is playful and emotional
juliet, who is innocent and youthful
lady capulet, who is sad and neglectful

Explanation:

In "Romeo and Juliet", the Nurse's coarse, motherly nature contrasts (acts as a foil) with Juliet's innocence and youth. Romeo is from a different family and not the main contrast here for the Nurse. Mercutio has a playful, witty, not mainly motherly - contrast - related role. Lady Capulet is more distant/neglectful, not the key foil for the Nurse's motherly coarseness compared to Juliet's innocence.

Answer:

C. Juliet, who is innocent and youthful