Final answer:
Increased source-to-skin distance is the most effective means of radiation protection for radiographers performing mobile procedures.
Step-by-step explanation:
The single most effective means of radiation protection for the radiographer performing mobile procedures is **b) Increased source-to-skin distance**. By increasing the distance between the radiographer and the radiation source, the radiation intensity decreases, reducing the risk of exposure. This is because the intensity of radiation drops inversely proportional to the square of the distance. In addition to increasing distance, other important radiation protection measures include minimizing exposure time and using proper collimation. Minimizing exposure time reduces the overall dose received, while proper collimation focuses the radiation beam to the specific area of interest, reducing unnecessary exposure to other body parts. While the use of a lead apron provides some radiation protection, it is not the single most effective means of protection. It primarily shields the body from scattered radiation rather than reducing the exposure from the primary radiation beam.