How Was the Proscenium Stage of the Romantic Theatre Modified

How was the proscenium stage of the romantic theatre modified to accommodate realist drama?

A) The acting area was huge with little area backstage to store scenic elements.
B) Box sets were made exactly to scale with full-dimension walls and real bookcases,windows,and fireplaces;in some instances,the proscenium arch was removed.
C) The audience sat on stage with the actors to feel like they were actually "in the scene" with all the actors.
D) The stage was physically raised and curtains were eliminated to reinforce the realist view that drama was "life on a pedestal."