What type of structure is in the scene where Julia and Winston go to O'Briens home? out of these 3 which is it and why: dramatic: sequence of events...

I believe
Chapter 16 is a dramatic chapter.  It has all the hallmarks of dramatic literature (, ,
symbolism), and it builds to a powerful conclusion, although the resolution is
unclear.

The chapter might stand alone as short dramatic one-act.  It begins
with a description of setting and has powerful dialogue, the most important of which is the
exchange between(Satanic figure) andand(Adam and Eve).  They are effectively selling their souls
to the Devil here:

You are prepared
to give your lives? Yes. You are prepared to commit murder? Yes.

To commit
acts of sabotage which may cause the death of hundreds of innocent people?  Yes.

To betray your country to foreign powers? Yes. You are prepared to cheat, to forge, to
blackmail, to corrupt the minds of children, to distribute...