I go for 'C'
As I've posted before in another thread, the way I see it - any time you see Bateman actually killing someone, it's all in his head. The few instances where he actually tries to murder someone, he cant do it - his inability to strangle Louis in the mens toilet and kill Jean with the nailgun in his apartment spring to mind.
Took me a few viewing to work all the pieces out. He can be nasty and brutal as hell with people (the 2 prostitutes) but he cant kill, he just imagines he does.
The clincher for me was when he shoots at the cop car and it explodes into flames from just a few bullets. From the look he gives the gun, you can see that Patrick is genuinely perplexed that a hand gun was enough to make the car explode in such a fashion, and for the 1st time is starting to have doubts about his sanity and what is real or not.
Nevermind American Psycho 2 saying that he did actually kill because, c'mon, American Psycho 2 was a pile of garbage that should never have been filmed. No-one should treatr that movie as cannon.