In 2010, jones committed an armed robbery. in 2015, the kentucky legislature enacted a law increasing the punishment for armed robbery from 15 to 20 years in prison. six months later, jones was captured, tried, convicted, and sentenced to 20 years in prison. sentencing jones to 20 years violates the:

Article I, Section 10 - Ex post facto clause

Sentencing Jones to 20 years violates the article I, section 10 or the Ex Post Facto Clause. This law retroactively changes the legal status, rules of evidence or consequences of actions that were committed before the enactment of the law. Moreover, in criminal law, it may change the punishment prescribed for a crime, as by adding new penalties or extending sentences and this was the case of Jones, which was prohibited by the U.S. Constitution.  

d is the best answer for this question.

a and b!

dfroos means which is a and b