A 4-year-old boy presents with a chronic cough and swollen lymph nodes. His records show that he has been given antibiotics several times in the past year with limited success, most recently for a liver abscess, and that he also has a recurring fungal skin condition. Which of the following is his most likely diagnosis?
A. Selective IgA deficiency
C. A deficiency in IgG2 subclass antibodies
D. Chronic granulomatous disease