A 30 year old unmarried women of average socio-economic background believes that her boss is an secretly love with her.She rings him up at odd hours and writes love letter to him despite his serious warning to do so.She holds this belief despite contradiction from family members and his denial.However she is able to manage her daily activities as before.She is most likely to be suffering from -

• A. Delusional disorder
• B. Depression
• C. Schizophrenia
• D. No psychatric ailment