A 25-year-old woman is seen by a physician because of Raynaud's phenomenon, myalgias, arthralgias, and difficulty in swallowing. There is no evidence of renal disease. An ANA titer is 1:5120 with a speckled pattern with mitotic. Which of the following is also likely to be found in this patient?

a) Rheumatoid factor
b) Anti-dsDNA antibodies
c) Anti-Smith antibodies
d) Anti-RNP antibodies