What's the potential mechanism of the patient's anemia?

22 year old male patient presenting with generalized weakness and ataxia. The patient has cystic fibrosis. On examination, pallor is noted, the patient has absent knee jerk reflexes and other deep tendon reflexes are difficult to initiate. Vibration sense is lost. Lab results showed evidence of anemia with elevated bilirubin and low haptoglobin. What’s the potential mechanism of the patient’s anemia?
A- drug induced destruction of RBCs
B- defective DNA formation
C- autoimmune destruction of RBCs
D- oxidative damage of RBCs
E- Sickling of Hemoglobin in patient’s acidotic blood