A 32-year-old woman presents to rheumatology clinic with a 4-month history of symmetric polyarthritis affecting her hands, wrists, and knees. She reports morning stiffness lasting 3 hours that improves with activity. On examination, she has swelling, warmth, and tenderness of the metacarpophalangeal and proximal interphalangeal joints bilaterally. Laboratory studies reveal: rheumatoid factor 145 IU/mL (normal <14), anti-CCP antibodies positive, ESR 58 mm/hr, and CRP 12 mg/dL. Synovial fluid analysis shows 8,500 WBC/µL with predominance of neutrophils. Synovial biopsy demonstrates hyperplastic synovial lining layer, pannus formation with fibroblasts and macrophages, and perivascular lymphocytic infiltration. Which of the following best describes the primary immunologic mechanism underlying her synovitis?

1. A)Type I hypersensitivity with mast cell and basophil degranulation in the synovium
2. B)Type III hypersensitivity with circulating and in situ immune complex deposition and complement activationGABARITO
3. C)Type II hypersensitivity with IgG antibodies against joint-specific autoantigens
4. D)Type IV hypersensitivity mediated by CD8+ cytotoxic T lymphocytes targeting synovial cells
5. E)Granulomatous inflammation with noncaseating granulomas and epithelioid macrophage accumulation