which of the following illustrates the inverse square law.. distance is rather ineffective protection from radiation

which of the following illustrates the inverse square law?

a- distance is amost effective protection from radiation

b- distance is rather ineffective protection from radiation

c- as distance from the radiation the source decreases radiation

decreases:
a- 1only
b- 1 and 2 only
c- 1 and 3 only
d- 2 and 3 only