According to the NCRP, personnel protective lead aprons used during fluoroscopy should be at least:

The correct answer is that personnel protective lead aprons used during fluoroscopy should be at least 0.50 millimeters of lead equivalent, as established by the National Council on Radiation Protection and Measurements (NCRP). The NCRP sets safety standards to ensure adequate protection for healthcare workers exposed to radiation during procedures like fluoroscopy, where the risk of radiation exposure can be significant.

Lead aprons function by attenuating scatter radiation, thereby reducing the amount of radiation that reaches the individual's body. A lead equivalent thickness of 0.50 millimeters is recognized as an effective standard for minimizing radiation exposure during these procedures, balancing protective benefits with the weight and usability of the aprons. Ensuring personnel have access to adequate protective equipment is critical for their safety in medical environments where radiation is present.

The options with lesser or greater lead equivalent may not provide the optimized protection required for fluoroscopy, which is why they do not meet the standards set by the NCRP for personnel safety during such exposures.