What Do Agents Such as Chemicals,elevated Temperatures,ionizing Radiation,and Viruses Have

What do agents such as chemicals,elevated temperatures,ionizing radiation,and viruses have in common?

A) Nothing
B) They can increase the frequency of mutations in only those members of the population who are already genetically impaired.
C) They are all mutagens that may increase the frequency of occurrence of mutations.
D) They always cause spontaneous abortions during the first trimester of pregnancy.