If correlation coefficient between two variables is uncertain, it implies that

A. The central limit theorem B. The law of statistical regularly C. The law of inertia of large numbers D. None of the above

A. Sampling error B. Measurement error C. Coverage error D. Non-response error

A. Both (A) and (R) are true B. (A) is true, but (R) is false C. (A) is false, but (R) is true D. Both (A) and (R) are false

A. 0 B. 1 C. 0.4 D. 0.8