A 60 yrs old man is brought to a psychiatrist with a 10 year history,that he suspects his neighbours and he feels that whenever,he passes by they sneeze and plan against behind his back.He feels that his wife has been replaced by a double and calls police for help.He is quite well groomed alert,occasionaly consumes alcohol.The likely diagnosis is:

• A. Paranoid personality
• B. Paranoid schizophrenia
• C. Alcohol withdrawal
• D. Conversion disorder