Which of the following would reduce receptor exposure by one-half if it was not possible for the technologist to adjust the mAs?
a) Increase the distance between the radiation source and the receptor by doubling it.
b) Implement a material with higher attenuation properties between the radiation source and the receptor.
c) Employ a grid to reduce scatter radiation reaching the receptor.
d) Use a collimator to limit the area of radiation exposure on the receptor.