Which detail from the story the magic prison foreshadows the palace becoming a prison

Your answer is "Poor little thing!" he cried, as he sprang up; you too are shut within this terrible prison. This thick darkness must be as hard for you to bear as it is for me.". I meant C #EDITED

 I usually don't explain but here: So A is eliminated because it is not even talking about the prison, B is talking about it but I will come back to it, but C. C is talking about just a iron door shut, It can be from anywhere not only prisons have that so that is out and we are left with D, well we also have B too on the side so lets check out D. read from top... So it is talking about the prison and how it is in it but also it is DETAILED, Yes it is talking about him sprang up and talking about thick darkness, So I would choose D. WAIT I got it wrong it is C i did not see the for shadowing part very sorry. Lol My Bad EDITED

conclusions made on the basis of unstated or stated evidence are called inferences