Final answer:
Lead is the best shielding material to attenuate x-rays due to its high density and ability to absorb radiation.
Step-by-step explanation:
Lead is the shielding material of choice to attenuate x-rays. It is particularly effective compared to other materials like aluminum, tungstate, or any type of metal. The greater the density of a material, especially the density of electrons within it, the smaller the range of radiation that can pass through.