Which one of the following statements is true concerning radiation mutagenesis? 

A. The risk factor of hereditary disease for members of the public is approximately 1% per Sv. 

B. Radiation is quite strong mutagen. 

C. Radiation produces unique mutations not otherwise seen spontaneously. 

D. Radiation dose-rate was not found to affect the induction of mutations. 

E. The genetic doubling dose for humans has been estimated at 1-2 Sv