Which character has undergone transformation in the story and state a close reference to the text?
This one will be a bit challenging to answer, primarily because the work is not mentioned. However, when examining transformation of characters in any work of literature, I would pay attention to a few things. The first would be to note in as many ways as possible how the character was at the start of the work, or at the start of their narrative. For example, in Macbeth, it's extremely important to examine the characteristics of the main character at the start of his transformation. This means noting body language, ideas/ thoughts, in what the person believes, and how they interact with others. As you note this, continue to pay attention to the conflicts they face in the course of the work. What are these conflicts, with whom do they concern, and how the main character reacts to these conflicts are of critical importance for these are the events/ moments that will provide the fodder for transformation. In many works of character transformation, there are seminal events that are responsible for such change/ evolution. Noting these are of critical importance. For instance, in West Side Story, when Tony meets Maria for the first time, or when Tony sees Riff stabbed represent critical moments of change in Tony. Finally, note how the characters "end up" at the end of the work. From where to where have they travelled, emotionally and psychologically? How have they changed from who they were to who they are at that point? In Oedipus, the vision of the man we have at the end of the story is far from the vision we have at the start. This represents evolution, transformation, and the height of a storyteller's prowess and skill.