Nisha,23 yrs old woman has experienced episodes of myalgias,pleural effusion,pericarditis and arthralgias without joint deformity over course of several yrs.The best laboratory screening test for diagnosis her disease would be:

• A. Erythrocyte sedimentation rate
• B. CD4 lymphocyte count
• C. Assay for thyroid hormones
• D. Antinuclear antibody