Jack Believes That the FBI Has Wire Tapped His Phone

Jack believes that the FBI has wire tapped his phone. He regularly checks his house for bugging devices. When he leaves the house, he always checks each window and takes a different route to his destination. Jack buys bottled water because he believes the FBI may try to poison his water. Jack is exhibiting the most common delusional disorder, which is

A) paranoid psychosis.
B) schizophrenia.
C) the erotomanic type.
D) the histrionic type.