Final answer:
The United States has the highest prisoner per capita rate among the listed countries, with over 700 prisoners per 100,000 people, and holds the largest number of prisoners in the world. Option A is correct.
Step-by-step explanation:
Among the countries listed: the United States, Russia, South Africa, and Mexico, the United States has the largest population of prisoners per capita. With an incarceration rate of over 700 persons per 100,000 of the national population, it is significantly higher than that of Russia, South Africa and Mexico. The U.S. is known for having about 2.1 million individuals imprisoned, which is the highest number in the world.
Furthermore, approximately one in every 40 U.S. citizens is under some form of correctional supervision. The American criminal justice system has seen its prison and jail population surge since the 1980s due to 'get tough on crime' initiatives and has been criticized for its mass incarceration approach as a principal crime prevention tool.