What country has the highest incarceration rate in the world?

Choices:
A. USA
B. Mexico
C. not enough information
D. Italy
USA
As his days in office wane, U.S. President Barack Obama is pushing to commute sentences of non-violent drug offenders convicted under what the White House called "outdated and unduly harsh" sentencing laws. It has become the centerpiece of his effort to reform the country’s criminal-justice system, which has the highest incarceration rate in the world.
Last Friday, the President granted commutations to 42 convicted nonviolent offenders, bringing the total so far in his presidency to 348 commutations — more than any president has in nearly half a century. His predecessor, George W. Bush granted clemency in just 11 cases.
It's not just Obama pushing for reform. Top Republicans and Democrats in Congress also support relaxing the sentencing laws that have tripled the federal and state prison populations in the last 30 years, reaching more than 1.56 million inmates at the end of 2014.
However in Congress, the main legislative effort for sentencing changes, the Sentencing Reform and Corrections Act of 2015, has failed to pass either chamber of Congress. The bill would reduce long mandatory minimum sentences for many nonviolent drug crimes, give judges more control over the terms of punishment and provide inmates with more opportunities to get out early by participating in rehabilitation programs.
Failing congressional help, Obama has in recent months relied on his presidential powers to commute the sentences of non-violent offenders.
Under the Constitution, the president has the power to grant “pardons for offenses against the United States” or to commute federal sentences. A pardon is an act of presidential forgiveness and wipes away any remaining legal liabilities from a conviction. A commutation reduces a sentence but does not eliminate a conviction or restore civil rights lost as a result of the conviction.
The American Bar Association has joined Obama's push and put its support behind the Clemency Project 2014, a national effort by multiple justice groups to help inmates who meet U.S. Department of Justice criteria apply for sentence commutations.