158Risk classified as unknown unknowns (i.e. those which cannot be identified or evaluate

158 Risk classified as unknown unknowns (i.e., those which cannot be identified or evaluated): A. should be deflected to the contracting officer

B. should be handled via contingency allowances

C. should be ignored, since they cannot be identified

D. should be ignored, since they are not covered in the Project Risk Assessment

E. C and D

请帮忙给出正确答案和分析，谢谢！