A 55-year-old woman presents with 5 weeks of significant depression following the sudden death of her husband. She reports difficulty sleeping，a 5kg weight loss，frequent crying spells，and profound guilt over surviving her. For the last week，she has been convinced that her body is literally decaying. She admits to seeing her husband''s face during the day，as well as hearing his voice telling her to kill herself and join him. Which of the following diagnosis is most likely
A: Major depression with psychotic features
B: Schizophrenia
C: Schizoaffective disorder
D: Adjustment disorder
E: Psychosis secondary to a general medical condition