This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Osteology, Subject name: Pathology
A 60-year-old woman with arthritis suffers a massive stroke and expires. At autopsy, the proximal phalangeal joint tissue shows pannus, synovial cell hyperplasia, and lymphoid follicles. Which of the following best describes the pathogenesis of pannus formation in this patient? 
Select and explain. 
A. Calcification of the synovium, B. Chronic inflammation of synovium, C. Degeneration of cartilage, D. Dislocation of a portion of bone
B: Chronic inflammation of synovium
Answer: B: Chronic inflammation of synovium 
Explanation: Rheumatoid arthritis (RA) is a systemic, chronic inflammatory disease in which chronic polyarthritis involves diarthrodial joints symmetrically and bilaterally. Synovial lining cells undergo hyperplasia. The result is a synovial lining thrown into numerous villi and frond-like folds that fill the peripheral recesses of the joint. As the synovium undergoes hyperplasia and hypertrophy, it creeps over the surface of the articular cartilage and adjacent structures. This inflammatory synovium is termed a pannus (cloak). The pannus covers the articular cartilage and isolates it from the synovial fluid. Synovial calcification (choice A) does not occur in RA. Pannus may destroy cartilage (choice C) by depriving it of nourishment.Diagnosis: Rheumatoid arthritis