A. This could be accurate, but the key here is that Delia only shows occasional symptoms. That means this isn't the best answer.
B. Catatonic subtype would mean she shows significant decreases or disturbances in movement, up to the point of no voluntary movement. This is a wrong answer.
C. Paranoid subtype would include dramatic symptoms, so this must be wrong as well.
D. Residual is the best answer. Delia has very few symptoms, and they are relatively blunted symptoms compared to the other options.
Hope this helps!