The first two. Christopher Lloyd's character, Judge Doom, is the big conspirator organising the whole situation, but it's the head of Roger's studio, R. K. Maroon, who does the actual setup.
He was the one to setup the situation between Acme and Jessica (the patty-cake), and he was also the one to hire Eddie Valiant to take pictures of the meeting. Then later when Valiant meets with Maroon to show him the results, they show Roger the pictures and he runs off to write his love poem, causing him to not have an alibi for the murder.
Judge Doom convinces Maroon to do all of this by agreeing to buy his company, but only if he can also buy Acme at the same time. However it was never Maroon's intention for there to be a murder, he was just hoping to blackmail Acme into selling.
No, you gotta understand, Valiant, I had nothin' to do with Acme gettin' killed. I just wanted to sell my studio. But they wouldn't buy my property unless Acme would sell his. And he wouldn't. So I was gonna blackmail Acme with pictures of him and the rabbit's wife.