In the United States, the Following Interrogation Techniques Are Legal

In the United States, the following interrogation techniques are legal EXCEPT:

A) telling the suspect that he will get a reduced sentence if he confesses to the crime.
B) assembling a phony lineup and telling the suspect he was identified by a witness.
C) holding the suspect in a cell without visitors or phone calls for 2 weeks.
D) having a police informant pose as a cellmate and testify in court about the suspect.