What Do Radiation Weighting Factors Take into Consideration

What do radiation weighting factors take into consideration?
1) The overall risk of exposure to humans from ionizing radiation
2) Both the internal and external dose measurements
3) The fact that some types of radiation are more efficient at causing biologic damage than other types of radiation for a given dose.

A) 1 only
B) 2 only
C) 3 only
D) 1,2,and 3