A 60-year-old patient visited his general practitioner because of fatigue and unexplained bruising. ...

A 60-year-old patient visited his general practitioner because of fatigue and unexplained bruising. Physical examination revealed a frail, thin, pale man with widespread bruising.
 
  A CBC was ordered and revealed abnormal granularity of platelets and leukocytes. Red cells appeared dimorphic. Bone marrow analysis showed 20 ringed sideroblasts with
  dysplastic changes in RBC and WBC precursors. No cytogenetic abnormalities were detected. Based on this information, what is a probable diagnosis?
 
  a. Acute leukemia
  b. Chronic lymphocytic leukemia
  c. Myelodysplastic syndrome
  d. Myeloproliferative syndrome