In Act 3 of "Romeo and Juliet," Juliet's character development can be understood through her responses to her parents and the Nurse, as she indeed exhibits all of the mentioned traits.
A. Juliet becomes stronger and starts to stand up for herself: As her circumstances become dire, she begins to assert herself more, especially when she confronts her parents about her feelings.
B. She is determined to control her own fate: Juliet demonstrates a desire to take control of her own destiny, particularly in her love for Romeo, even in the face of her parents' expectations.
C. She feels disillusioned and betrayed by the Nurse: When the Nurse advises her to marry Paris after Romeo is banished, Juliet feels abandoned and betrayed, which leads to a significant shift in her trust.
Given these key aspects of her character development, the answer is D. All of the above. Juliet's growth throughout Act 3 illustrates her increasing strength, independence, and the emotional turmoil she faces.